CVE-2026-119234 json
mvfst did not adequately merge or compact out-of-order STREAM frame data, and a small received fragment could keep a much larger receive bu…
published 17h ago modified 17h ago also EUVD-2026-123604
- cvss
- —
- not scored
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- —
- no EPSS score yet
- public exploits
- 0
- none known
Summary
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.
Patch / fix
Is CVE-2026-119234 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerAffected products
- Facebook mvfst
References
Sources
- CVE List CVE-2026-119234
- NVD CVE-2026-119234
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.