CVE-2026-119234
CVE-2026-119234
mvfst did not adequately merge or compact out-of-order STREAM frame data, and a small received fragment could keep a much larger receive buffer alive. QUIC flow control limits the number of buffered stream bytes, but not this per-fragment memory and bookkeeping. A remote, unauthenticated QUIC peer could send many small, non-contiguous stream fragments to make an endpoint consume memory far in excess of its advertised receive window and spend increasing CPU time reassembling stream data, leading to denial of service. This issue affects mvfst versions prior to v2026.11.09.0.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| mvfst |
≥ v0.0.0.0; < v2026.11.09.0 (affected, semver)
Other versions: unaffected |
CNA: Meta |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
No CVSS assessment reported. An unscored record is not a low-severity determination.
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://www.facebook.com/security/advisories/cve-2026-119234CNA: Meta · x_refsource_CONFIRM
- https://github.com/meta/mvfst/commit/7e5cff58e8cbed87793141ceeca0a8a343c67c44CNA: Meta · x_refsource_MISC
- https://github.com/meta/mvfst/commit/7e5cff58e8cbed87793141ceeca0a8a343c67c44[email protected]
- https://www.facebook.com/security/advisories/cve-2026-119234[email protected]
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