Is CVE-2026-119233 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-119233 being exploited in the wild.

How severe is CVE-2026-119233?

Informational severity, published 11 November 2026.

Which products and versions are affected?

Meta Proxygen before v2026.11.09.00.

Is there a fix for CVE-2026-119233?

Yes: fixed in v2026.11.09.00. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-119233 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-119233?

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.

CVE-2026-119233: Meta proxygen HTTP/3 denial of service in frame buffering

CVE-2026-119233 · Severity: info · Published 2026-11-11

Meta's proxygen is a C++ HTTP library used to handle web communication protocols. An attacker can cause unbounded memory and CPU consumption by slowly sending an incomplete HTTP/3 frame with a very large declared size, leading to denial of service and potential service outages.

Technologies: Meta Proxygen. Vendors: Meta.

Quick answers

Is CVE-2026-119233 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-119233 being exploited in the wild.
How severe is CVE-2026-119233?: Informational severity, published 11 November 2026.
Which products and versions are affected?: Meta Proxygen before v2026.11.09.00.
Is there a fix for CVE-2026-119233?: Yes: fixed in v2026.11.09.00. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-119233 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-119233?: 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: v2026.11.09.00

Technical details

The HTTP/3 codec in proxygen lacks bounds checking when buffering incomplete non-DATA frames (control-stream, HEADERS, or unknown frame types) and rescans all buffered data on each incoming byte fragment, causing quadratic CPU growth. A remote, unauthenticated attacker on the network can trigger this via a single HTTP/3 connection by declaring a massive frame length and delivering it slowly in small fragments. The vulnerability affects proxygen before v2026.11.09.00.

Affected products

Meta proxygen before v2026.11.09.00

Timeline

2026-11-11: disclosed
2026-11-09: patched

References

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