CVE-2026-119236: An mvfst QUIC server retained CRYPTO frame data received at an encryption level (Initial or
Source GCVE Database
Not known to be exploited : upgrade to v2026.11.09.00 soon.
Data as of 11 Nov 2026, 20:03 UTC
Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD
Thin evidence
One scorer or none- Patch
- Available – fixed in v2026.11.09.00, 2026.11.09.00
Exploitation evidence
Disclosed: evidence found.
CVE published 11 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
What to do
Upgrade mvfst to v2026.11.09.00; meta/mvfst to 2026.11.09.00.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Facebookmvfst | Affected
| Fixed in
|
GitHubmeta/mvfstpkg:github/meta/mvfstOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade mvfst to version v2026.11.09.00 or later, where this issue is fixed. No other mitigation or workaround is indicated.
Description
An mvfst QUIC server vulnerability allows a remote unauthenticated client to cause unbounded memory growth by sending Handshake-level CRYPTO data after the TLS handshake has progressed past that encryption level. This can lead to denial of service. The issue affects mvfst versions prior to v2026.11.09.00.