CVE-2025-8671
HIGHEPSS 90th pctlDescription
A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.
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
High risk: more likely to be exploited than 90% of all known CVEs.
References
- https://galbarnahum.com/made-you-reset
- https://github.com/h2o/h2o/commit/4729b661e3c6654198d2cc62997e1af58bef4b80
- https://github.com/h2o/h2o/security/advisories/GHSA-mrjm-qq9m-9mjq
- https://gitlab.isc.org/isc-projects/bind9/-/issues/5325
- https://kb.cert.org/vuls/id/767506
- https://support2.windriver.com/index.php?page=security-notices
- https://varnish-cache.org/security/VSV00017.html
- https://www.fastlystatus.com/incident/377810
- https://www.suse.com/support/kb/doc/?id=000021980
- http://www.openwall.com/lists/oss-security/2025/08/13/6
- http://www.openwall.com/lists/oss-security/2025/09/18/1
- https://deepness-lab.org/publications/madeyoureset/
- https://github.com/Kong/kong/discussions/14731
- https://github.com/envoyproxy/envoy/issues/40739
- https://github.com/varnish/hitch/issues/397
- https://www.imperva.com/blog/madeyoureset-turning-http-2-server-against-itself/
- https://www.kb.cert.org/vuls/id/767506
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Start freeThis 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 2025-11-04.