CVE & CISA-KEV Catalog

A missing release of backend receiver sessions in the Ad Hoc Transfer component of Progress Software WS_FTP Server versions prior to 2024.0.7 and 2025.0.4 on Windows could lead to server resource exhaustion and service degradation.

Published 2026-10-29

P-Net before 1.0.3 does not release the RPC session allocated for an RPC request that names an unknown interface or object UUID, and does not start a timeout for it. Repeated requests with different activity UUIDs exhaust the available sessions. Once they are exhausted the device no longer answers new RPC requests, including Endpoint Mapper Lookup and Connect, until it is restarted. A remote unauthenticated attacker can use this to cause a denial of service.

Published 2026-10-29

P-Net before 1.0.3 does not release the Application Relationship (AR) and the RPC session when an RPC request is rejected because its data representation has incorrect endianness. The session and its AR remain allocated, so repeated requests exhaust the available sessions. Once they are exhausted the device no longer answers new RPC requests, including Connect, until it is restarted. A remote unauthenticated attacker can use this to cause a denial of service.

Published 2026-10-29

Echo is a Go web framework. From 4.15.0 until 4.16.1 and 5.4.1, Echo's Proxy middleware can retain a handler, copy goroutines, and network connections after a WebSocket client disconnects when the upstream keeps its connection open. The raw proxy waits for both copy directions without reliably closing the peer connection when one direction ends, including when a rejected upgrade response uses HTTP keep-alive. Repeated connections can accumulate resources and cause denial of service, depending on proxy-route accessibility, upstream behavior, and connection deadlines. This issue is fixed in 4.16.1 and 5.4.1.

Published 2026-10-28

The Bluetooth host pre-allocates a bt_conn object (a "reservation") from the fixed acl_conns[] pool for every connectable advertising set it starts, in le_adv_start_add_conn() in subsys/bluetooth/host/adv.c. When an incoming peripheral connection completes, find_pending_connect() in subsys/bluetooth/host/hci_core.c looked that reservation up using only the identity and the peer address, with a directed-then-undirected fallback, and had no knowledge of which advertising set actually terminated. With CONFIG_BT_EXT_ADV_MAX_ADV_SET > 1, where the LE Enhanced Connection Complete event is cached until the LE Advertising Set Terminated event identifies the set, this lookup can return the reservation belonging to a different, still-running advertising set. The defect is reachable over the air by

Published 2026-10-26

storage/pkg/archive.ApplyLayer and ApplyUncompressedLayer may, when processing corrupt or malicious inputs, leak a file descriptor; unbounded repeated calls can exhaust the process’ file descriptor limit

Published 2026-10-21

One logical thread of a user-mode ThreadX module costs the Module Manager's shared object pool two allocations, not one. The module asks for a `TX_THREAD` control block through `txm_module_object_allocate`; `_txm_module_manager_thread_create` then takes a second allocation of `TXM_MODULE_KERNEL_STACK_SIZE` bytes for the privileged kernel stack that thread's system calls run on, and records it in the control block. Both come from `_txm_module_manager_object_pool` and both are linked onto the module's allocation list. The Module Manager's thread-delete dispatcher released only the first. The kernel stack stayed allocated until the whole module was stopped, so a module that creates, terminates and deletes threads in a loop — every state transition valid, every service returning `TX_SUCCESS

Published 2026-10-20

A flaw was found in nfs-utils. An unauthenticated remote attacker can trigger a Denial of Service (DoS) by sending repeated state notification requests to an exposed rpc.statd service. The service fails to properly release memory allocated during callback processing, leading to continuous memory growth. Sustained requests can exhaust system resources, eventually causing the service to degrade or crash.

Published 2026-10-16

The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). From 1.8.0 until 1.30.0 and 2.2.0, stateful Streamable HTTP servers, including FastMCP, MCPServer, Server.streamable_http_app(), and StreamableHTTPSessionManager, retain session entries without an idle expiration or aggregate session-count limit. DELETE, refused opening requests, and completed sessions do not reliably discard their entries, and each entry can retain parsed initialize parameters. A client that can reach the endpoint can therefore create ordinary short requests that grow server memory without bound until restart. Stateless HTTP, stdio, and SSE transports are not affected. This issue is fixed in versions 1.30.0 and 2.2.0.

Published 2026-10-14

Libreswan in FIPS mode has a vulnerability where badly formed received certificates are rejected, but not deleted from the NSS cache. As a result, any real certificates with the same serial number are rejected as well. This can be abused to lock out legitimate peers from connecting. The add_decoded_cert() function missed a call to CERT_DestroyCertificate() due to an incorrect fix for CVE-2026-14957. Sending bogus certificates with new serial numbers could prevent the real certificates with those serial numbers from connecting until the service has restarted.

Published 2026-10-13

The Bluetooth Mesh Access layer delayable-message machinery in subsys/bluetooth/mesh/delayable_msg.c manages a static pool of CONFIG_BT_MESH_ACCESS_DELAYABLE_MSG_COUNT message contexts (default 4) threaded onto a free_ctx or busy_ctx list. release_delayable_msg_ctx() returned a context to free_ctx only when sys_slist_find_and_remove() found it on busy_ctx. The chunk-exhaustion error path in bt_mesh_delayable_msg_manage() releases a context that was already popped off free_ctx but not yet inserted on busy_ctx, so the context was appended to neither list and was permanently lost from the pool. Because bt_mesh_delayable_msg_init() runs only once from bt_mesh_init(), and node reset/suspend only drain busy_ctx, the loss survives unprovision, re-provision and suspend/resume — it is cleared only

Published 2026-10-13

IBM Power Systems Firmware FW1110.00 through FW1110.31, FW1120.00 through FW1120.01, and FW1060.00 through FW1060.81 could allow a remote authenticated attacker to cause a denial of service by exhausting connection resources due to improper resource management.

Published 2026-10-12

The Link Layer Control Procedure (LLCP) implementation of the Zephyr software Bluetooth LE Controller retains the receive node that carried an accepted LL_PHY_UPDATE_IND so that it can later be reused for the host notification when the update instant is reached (llcp_rx_node_retain() in subsys/bluetooth/controller/ll_sw/ull_llcp.c, and the node is deliberately not recycled while marked NODE_RX_TYPE_RETAIN). The invalid-PDU arms of llcp_lp_pu_rx() and llcp_rp_pu_rx() in subsys/bluetooth/controller/ll_sw/ull_llcp_phy.c completed the procedure via llcp_lr_complete() / llcp_rr_complete() without first releasing that retained node, so the procedure context — the only remaining reference to the node — was freed while the node was still held out of the receive pool. A peer device on an establish

Published 2026-10-11

The Bluetooth Link Layer control procedure code in subsys/bluetooth/controller/ll_sw/ull_llcp_conn_upd.c retains the received RX node while a Connection Update / Connection Parameter procedure waits for its instant, so the node can later carry the host notification (llcp_rx_node_retain(), which marks it NODE_RX_TYPE_RETAIN and thereby suppresses the normal recycling in ull.c). The default: arm of llcp_rp_cu_rx() and llcp_lp_cu_rx() — the "invalid PDU, terminate the connection" path — completed the procedure without releasing that retained node. llcp_rr_check_done() then dequeued and freed the procedure context with ctx->node_ref.rx still pointing at the retained node, dropping the last reference to it. A peer device in radio range can reach this without pairing, bonding, or encryption. Ag

Published 2026-10-11

Missing release of memory after effective lifetime, Missing release of resource after effective lifetime vulnerability in Apache Thrift THeaderTransport. This issue affects Apache Thrift: before 0.25.0. Users are recommended to upgrade to version 0.25.0, which fixes the issue.

Published 2026-10-10

OWASP Coraza WAF is a golang modsecurity compatible web application firewall library. From 3.0.0 until 3.8.0, the multipart loop in internal/bodyprocessors/multipart.go executes defer temp.Close() for every uploaded file part, so each temporary-file descriptor remains open until the complete request returns. An unauthenticated attacker can submit a multipart body containing many minimal file parts and exhaust the process file-descriptor table within the request-body size limit, causing os.CreateTemp failures, MULTIPART_STRICT_ERROR responses, blocked legitimate uploads, and process-wide inability to open files or sockets. This issue is fixed in version 3.8.0.

Published 2026-10-09

A missing release of resources in the illumos name service cache daemon (nscd) allows a local user to exhaust kernel memory. The nscd door server procedure, switcher() in usr/src/cmd/nscd/nscd_frontend.c, does not close file descriptors that are passed with a door call but not used by the request, and the main nscd door at /var/run/name_service_door accepts passed descriptors from any user in its zone. Because nscd also runs with an unlimited file descriptor limit, an unprivileged local user, including one in a non-global zone, can repeatedly pass a descriptor to its zone's nscd in a door_call() loop, causing the file descriptor table of nscd to grow without bound in kernel memory. This causes a denial of service of nscd and can render processes in all zones on the host unresponsive. The f

Published 2026-10-09

Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 2.10.0 until 2.53.0, streamed requests made through ConcurrencyLimitedModel or limit_model_concurrency can retain shared concurrency slots because anyio.CapacityLimiter associates an acquired slot with the borrowing task while streaming cleanup can run in a different task. Early stream termination, cancellation, consumer exceptions, or complete stream_text() consumption with debounce_by=0.1 can therefore leave capacity occupied, eventually preventing later requests that share the long-lived limiter from proceeding and causing a denial of service. Agent-level max_concurrency and non-streaming model requests are not affected. This issue is fixed in version 2.53.0.

Published 2026-10-08

improper handling of exceptional conditions, Missing release of resource after effective lifetime vulnerability in Apache Thrift java bindings. This issue affects Apache Thrift: before 0.25.0. Users are recommended to upgrade to version 0.25.0, which fixes the issue.

Published 2026-10-07

A flaw was found in SSSD. A local user can trigger a Denial of Service (DoS) by exploiting a race condition in the autofs responder between asynchronous enumeration completion and map invalidation. By repeatedly sending concurrent map enumeration and invalidation requests, an attacker can cause memory to leak, leading to excessive memory consumption that can disrupt or crash the autofs service.

Published 2026-10-06

A flaw was found in SSSD. An issue in the Kerberos Credential Manager (KCM) responder allows a local user to cause a Denial of Service (DoS) by maintaining a persistent connection and repeatedly storing and destroying credentials. Because the service fails to release cached objects from memory when credentials are removed, memory consumption grows continuously, ultimately exhausting available memory and rendering the service unresponsive.

Published 2026-10-06

A flaw was found in SSSD. In configurations where the autofs responder service is enabled, memory allocated during successful request processing is not released until the client connection terminates. A local attacker can exploit this vulnerability by maintaining an open connection and repeatedly submitting valid requests, leading to memory exhaustion and a Denial of Service (DoS).

Published 2026-10-06

In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: unregister debugfs entries on teardown ucsi_register() creates per-instance debugfs entries, but ucsi_unregister() keeps them around until ucsi_destroy(). Drivers like ucsi_glink that unregister/register the same UCSI instance across remoteproc restart then try to create an already existing debugfs directory and log: debugfs: 'pmic_glink.ucsi.0' already exists in 'ucsi' Unregister debugfs entries as part of ucsi_unregister(), and clear ucsi->debugfs after freeing it so repeated unregister paths remain safe.

Published 2026-10-03

Wind River VxWorks 7 prior to 26.09, specific system call arguments can result in the IPNET subsystem failing to properly release allocated kernel memory and system file descriptors before terminating the calling application. Fixed in Version 26.09.

Published 2026-09-28

Missing release of resource after effective lifetime, Comparison using wrong factors vulnerability in Apache Tomcat allows a denial of service as a result of lost time outs for asynchronous WebSocket writes. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.0.M1 through 9.0.121. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.43 through 7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.

Published 2026-09-23

vLLM through 0.29.0 contains a resource exhaustion vulnerability in MooncakeConnector where rejected prefill requests create ownerless transfer placeholders that are never reclaimed. Attackers can send rejected requests to exhaust sender task pools, causing valid requests to be delayed by up to 480 seconds while health checks continue returning success.

Published 2026-09-21

Apache Karaf's XmlUtils cached XML parser/transformer factories in static ThreadLocal fields on long-lived container threads. Because a ThreadLocal value outlives the OSGi bundle that created it, repeated bundle or feature install, update, or refresh operations can leave successive bundle ClassLoader's pinned in memory and unreachable for garbage collection, leading to unbounded Metaspace growth and eventual denial of service of the Karaf instance.

Published 2026-09-17

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. From 3.0.8 until 3.0.12, a client with maxConnections or maxConnectionsPerHost set above zero leaks one connection permit whenever TLS connection establishment fails before the handshake completes. NettyConnectListener removes the partitionKeyLock permit from NettyResponseFuture before every failure path is bound to the channel closeFuture, so an abort can leave the permit unreleased. Repeated failures can permanently lock out one host under a per-host limit or drain the shared pool under a global limit, blocking later requests even when no connection remains open. The default unlimited connection setting is not affected. This issue is fixed in version 3.0.1

Published 2026-09-17

InternLM LMDeploy through 0.17.0 in DistServe prefill/decode disaggregation mode fails to release scheduler sessions because the proxy uses user-facing session IDs instead of internal scheduler keys. Unauthenticated attackers can send completion requests to the proxy endpoint that accumulate unreleased scheduler metadata and memory until the prefill worker is out-of-memory killed.

Published 2026-09-17

A vulnerability in Datagram TLS (DTLS) message handling of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software for Cisco Secure Firewall 3100 Series and 4200 Series devices could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper resource management when processing certain DTLS messages. An attacker could exploit this vulnerability by sending a crafted stream of DTLS traffic to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Published 2026-09-16

RMCP is an official Rust SDK for the Model Context Protocol. Prior to 2.0.0, the rmcp crate's stateful Streamable HTTP server in crates/rmcp/src/transport/streamable_http_server/tower.rs allows an unauthenticated client to send a well-formed JSON-RPC POST that is not an initialization request, or an initialization request with a mismatched protocol header, causing StreamableHttpService::handle_post to call LocalSessionManager.create_session before validating the message. An early validation failure returns without removing the inserted LocalSessionHandle from LocalSessionManager.sessions, permanently retaining session and channel state for the server process lifetime. Repeated requests can grow the shared session table without bound, degrade legitimate-client latency through lock contentio

Published 2026-09-16

undici's retry handler can leave an already-exposed response body pending forever. When a server returns a successful response that declares a Content-Length, sends only part of the body, and closes the connection, the retry handler retries the request. If the retry returns a non-retryable status such as 400, the handler forwards that new response downstream and replaces its internal response stream, but the original response body that the application still holds is never ended or destroyed. As a result calls that read that body never settle, and the configured body timeout does not fire because its timer is tied to the connection parser rather than the orphaned body. An attacker-controlled server can trigger this with two short responses without keeping a connection open, and repeated req

Published 2026-09-09

Missing release of resource after effective lifetime in Windows Secure Socket Tunneling Protocol (SSTP) allows an authorized attacker to deny service locally.

Published 2026-09-08

Missing Release of Resource after Effective Lifetime vulnerability in Erlang/OTP inets httpd allows an unauthenticated remote attacker to cause denial of service by sending valid request headers with a large Content-Length and then stalling before the body is complete. httpd_request_handler:handle_info/2 cancels the request timeout as soon as a parse step succeeds, which includes the headers, and the clause that handles a decoder asking for more data re-arms the socket with {active, once} without setting any further timer. httpd_request:whole_body/2 returns such a continuation whenever the bytes received are fewer than the announced Content-Length, so a well-formed request that stops mid-body leaves the worker waiting indefinitely. The periodic byte-rate check that would reclaim it is arm

Published 2026-09-08

A vulnerability was found in libsoup's HTTP/2 protocol implementation. The library fails to correctly release memory context blocks under specific stream termination conditions, such as when an HTTP/2 connection encounters window exhaustion or explicit stream resets. A remote, unauthenticated attacker acting as a malicious network peer can trick the connection engine into allocating stream states that are subsequently leaked during cleanup. Over a sustained period, this flaw allows the remote attacker to consume the system's heap allocations incrementally, triggering a denial of service (DoS) through an ultimate Out-of-Memory (OOM) application crash.

Published 2026-09-07

Missing Release of Resource after Effective Lifetime vulnerability in Erlang/OTP inets httpd allows an unauthenticated remote attacker to cause denial of service by sending a request with a chunked body whose chunk-size line is not a hexadecimal number. The worker serving the connection is never released and no timeout reclaims it, so repeating the request across connections occupies every available worker and denies service to legitimate clients. No authentication is required and the default configuration is affected. The chunk-size line must arrive in a write separate from the headers. When the body accompanies the headers, httpd_request_handler:handle_body/3 calls http_chunk:decode/3 inside a try ... catch throw:Error, so the {error, {chunk_size, _}} thrown by http_chunk:decode_size/4

Published 2026-09-03

When a container-level ErrorHandler is configured (the mitigation for finding 221000), each delivery whose processing throws still permanently consumes one link credit. After initialCredits (default 100) failing messages the receiver's credit reaches zero and the broker stops delivering, leaving the listener silently stalled while isRunning() remains true. Spring AMQP 4.1.0

Published 2026-08-27

libp2p is a JavaScript implementation of the libp2p networking stack. Prior to version 4.2.9, the reservation refresh path in reservation-store.ts reuses the same retimeableSignal but unconditionally registers another abort listener on every refresh. As a result, a remote peer can repeatedly send valid RESERVE requests for the same reservation, causing unbounded listener and closure growth in @libp2p/circuit-relay-v2 relay servers and leading to denial of service. This issue is fixed in version 4.2.9.

Published 2026-08-24

Missing Release of Resource after Effective Lifetime vulnerability in Apache CloudStack's scoped global configuration functionality. It affects different modules and plugins of the CloudStack management server, including Quota, Host-HA, etc., and may lead to eventual denial of service (DoS) scenario for the management server. This issue affects Apache CloudStack: from 4.7.0 through 4.20.3.0 and from 4.21.0.0 through 4.22.1.0. Users are recommended to upgrade to version 4.20.3.1 or 4.22.1.1 or later, which fixes the issue.

Published 2026-08-21

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.136.Final and 4.2.16.Final, io.netty.handler.codec.dns.AbstractDnsRecord, io.netty.handler.codec.dns.DefaultDnsRecordDecoder.decodeRecord(), and io.netty.handler.codec.dns.DnsCodecUtil.decompressDomainName() failed to release retained or newly allocated ByteBuf objects when IDN.toASCII() or encodeDomainName() rejected a malformed domain name, allowing unauthenticated remote DNS packets to leak direct memory incrementally until denial of service. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

Published 2026-08-13

Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.17.0, turnports_allocate_even() in src/apps/relay/turn_ports.c marks the unused odd sibling port as TPS_TAKEN_ODD for an EVEN-PORT Allocate request with reservation bit R=0 even though no RTCP socket will release it, allowing an authenticated client to permanently exhaust the relay port pool and cause subsequent allocations to fail with STUN error 508. This issue is fixed in version 4.17.0.

Published 2026-08-11

The UpdateHub over-the-air update client's start_coap_client() in subsys/mgmt/updatehub/updatehub.c leaks the CoAP/DTLS socket descriptor on its connection-setup failure paths. The shared error: cleanup gated socket closing on a ret > 0 flag, but ret was set to -1 immediately after the socket was created, so when zsock_setsockopt() (DTLS) or zsock_connect() subsequently failed the gate was false and cleanup_connection() was never called. The open descriptor in the global ctx.sock was then overwritten by the next attempt, permanently leaking it from the socket / net_context pool until reboot. The failing setup path is reached every time the OTA client tries to contact the UpdateHub server and the connection cannot be established — driven automatically by the periodic autohandler() poll (an

Published 2026-08-10

In Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 1.0.2.7 (1.0.X series), 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series), sensitive key material held by the AES and DESede engines, the SP 800-90A DRBGs, SymmetricSecretKey and the PBKD and scrypt parameter classes was zeroised on garbage collection by overriding Object.finalize. Finalization runs at an unspecified time and in an unspecified order and is serviced by a single finalizer thread, so where objects carrying a finalizer are allocated faster than that thread retires them the pending-finalization queue grows without bound: disposal falls arbitrarily far behind, which can contribute to an OutOfMemoryError under load, and the key material those objects hold stays resident in the heap for as long as they are queued, defeating the pu

Published 2026-08-08

Klever-Go is the Go implementation of the Klever blockchain protocol. In versions prior to 1.7.18, the account-data trie syncers are vulnerable to a resource-exhaustion flaw that leaks bounded throttler slots on error paths. In syncDataTrie() (in both userAccountsSyncer.go and kappAccountsSyncer.go), StartProcessing() reserves a slot from the NumGoRoutinesThrottler, but the corresponding EndProcessing() is only called on the success path and on the duplicate-root early return. As a result, any error from trie.NewTrie(), trie.NewTrieSyncer(), or trieSyncer.StartSyncing() (including the network-dependent timeout path) permanently consumes one slot for the lifetime of the throttler. An attacker who can repeatedly cause trie-node sync failures or timeouts during bootstrap can exhaust the bound

Published 2026-08-07

A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS XE Software could allow an authenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to improper error handling when parsing SNMP requests. This vulnerability affects all versions of SNMP — Versions 1, 2c, and 3. An attacker could exploit this vulnerability by sending a malformed SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly. The attacker must have the SNMPv1 or v2c read-only or read-write community string or valid SNMPv3 user credentials on the affected device.

Published 2026-08-05

In Eclipse Milo versions 1.0.0 through 1.1.4, monitored-item quota accounting is not exception-safe: if item creation fails with an unchecked error, the server-global reservation is not restored. Deeply nested PubSub ExtensionObjects in a `CreateMonitoredItems` event filter can trigger a `StackOverflowError` during decoding, allowing an unauthenticated remote client to exhaust a finite global monitored-item quota and prevent all clients from creating new monitored items until restart. Existing monitored items and other server functions remain unaffected.

Published 2026-08-04

HttpClient based on the classic i/o model fails to correctly release the underlying connection back to the connection manager if it encounters an invalid or unsupported `Content-Encoding` header value in the response message. Please note this defect does not affect HttpClient based on the async i/o model. This issue affects Apache HttpComponents Client: from 5.0-alpha1 through 5.6.2.

Published 2026-07-31

An unauthenticated attacker could trigger an Out of Memory condition to crash the Java process for RHCS by repeatedly sending HTTP requests to the TLS endpoint. Depending on how the RHCS server is configured, a manual intervention to restart it may prove necessary.

Published 2026-07-23

In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, client terminated DNS-over-QUIC (DoQ) queries are not accounted properly by Unbound resulting in low-cost inflation of the waiting number of replies for already in-flight resolution queries. This results in degradation of resolution service for new clients for already in-flight queries. A malicious actor can exploit the vulnerability by issuing DoQ queries for query names that need resolution and proceeding on immediately terminating the query by one of STOP_SENDING/RESET_STREAM/CONNECTION_CLOSE QUIC frames. Those terminated DoQ queries are not properly counted for and keep inflating the number of waiting replies for in-flight queries. When the maximum is reached, it results in silent query drops for new clients needing resolution fo

Published 2026-07-23

In NLnet Labs Unbound 1.20.0 up to and including 1.25.1, when Unbound is configured with 'serve-expired: yes' and 'serve-expired-client-timeout > discard-timeout > 0' (contrary to the suggested values), the discard-timeout branch during the serve expired logic drops an aged client reply without performing the correct accounting for the number of reply addresses for the query. Other identical branches outside of serve expired perform the correct decrement. Since the counter is never decremented in such scenario, it can reach the maximum limit and new clients for duplicate in-flight queries are silently dropped resulting in degradation of resolution service. A malicious actor can exploit the vulnerability by querying the resolver for a client-controlled slow-on-demand authoritative zone that

Published 2026-07-23