CVE-2026-48059
HIGHDescription
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, the HAProxy PROXY protocol v2 codec in netty leaks native or heap memory on every connection when a client sends a syntactically valid header containing nested `PP2_TYPE_SSL` TLVs (type-length-value records) at depth two or greater. The leak occurs on the successful parse path — no exception is thrown, the message fires downstream, the decoder removes itself, and the application releases the `HAProxyMessage` normally. Yet the underlying cumulation buffer (a pooled, potentially direct `ByteBuf` allocated by the channel) remains permanently pinned. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
How to fix
This vulnerability affects an unusually large number of packages. The highest-confidence fixes are shown above; the full list is longer. Check the referenced advisories for complete coverage.
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 48% of all known CVEs.
References
Related Vulnerabilities
Other CWE-401 (Missing Release of Memory (Memory Leak)) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2020-13934 | High | 7.5 | 64% | - | Fix |
| CVE-2016-6304 | High | 7.5 | 63% | - | Fix |
| CVE-2019-12265 | Medium | 5.3 | 60% | - | Fix |
| CVE-2001-0136 | Medium | 5.0 | 45% | - | - |
| CVE-2016-4232 | High | 7.5 | 36% | - | - |
| CVE-2001-0543 | Medium | 5.0 | 19% | - | - |
Common questions
How do I fix CVE-2026-48059?
Published advisories record a fix for 206 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.
Is CVE-2026-48059 being actively exploited?
Not that we know of. CVE-2026-48059 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.63% is the estimated probability that it will be exploited in the next 30 days. That is higher than 48% of all scored CVEs.
How severe is CVE-2026-48059?
CVE-2026-48059 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-48059 affect?
Published advisories record a fix for cryostat/cryostat (Red Hat / RHEL), cryostat/cryostat (Rocky), cryostat/cryostat-agent (Rocky), cryostat/cryostat-agent (Red Hat / RHEL), and 202 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-13.