CVE-2026-121737 facebook proxygen
facebook proxygen: no CVSS score yet. EPSS 0.2% estimated probability of exploitation activity in the next 30 days.
When a remote, unauthenticated HTTP/1.1 client pipelined the start of a second request and then stopped reading, proxygen's coroutine-based HTTP session could free that pipelined stream while resetting the connection's streams on the resulting write timeout, then go on to use it. This can crash the server, leading to denial of service, and may allow memory corruption with further impact. This issue affects proxygen versions prior to v2026.11.09.00.
- EPSS
- 0.2% estimated probability of exploitation activity in the next 30 days; 9th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- Published
- Modified
- Assigned by
- Meta (CNA)
- NVD analysis
- Deferred: the NVD does not plan to analyze it
- Record from
- the NVD, synced
Ask an AI about this CVE
Show the prompt
Explain CVE-2026-121737 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-121737?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-121737?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-121737 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Badge for a README or a site
An image that stays current: it is drawn from the data each time it is fetched (a host that proxies images, as GitHub does, may show its copy for a while). Markdown:
[](https://cve.bz/cve/CVE-2026-121737)
HTML:
<a href="https://cve.bz/cve/CVE-2026-121737"><img src="https://cve.bz/cve/badge/CVE-2026-121737.svg" alt="CVE-2026-121737"></a>
Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| Facebook proxygen | from v0.0.0.0 before v2026.11.09.00 |
History
- The NVD deferred its analysis
Changes since this site first stored the record. The same for every record: /api/public/changes.