Quick answers
- Is CVE-2026-119237 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-119237 being exploited in the wild.
- How severe is CVE-2026-119237?
- Informational severity, published 11 November 2026.
- Which products and versions are affected?
- Meta Proxygen prior to v2026.11.09.00.
- Is there a fix for CVE-2026-119237?
- Yes: fixed in proxygen v2026.11.09.00. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-119237 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-119237?
- Check whether you run Meta Proxygen at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: proxygen v2026.11.09.00
Technical details
The vulnerability occurs when HTTP/3 HEADERS blocks reference QPACK dynamic table entries that have not yet been received. Header decoding pauses for that stream, but the session continues reading from the QUIC transport, causing unread data to bypass buffer limits and be re-scanned repeatedly on each read cycle. A remote unauthenticated peer can exploit this with malformed headers followed by continuous data streams, triggering quadratic CPU growth and unbounded memory accumulation.
Affected products
- Meta proxygen prior to v2026.11.09.00
Timeline
- 2026-11-11: disclosed
- 2026-11-09: patched