CVE-2026-119234
mvfst Stream Fragment Denial of Service Vulnerability
Description
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.
INFO
Published Date :
Nov. 11, 2026, 5:17 p.m.
Last Modified :
Nov. 11, 2026, 5:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Solution
- Update mvfst to version v2026.11.09.0 or later.
- Ensure stream frame data is properly merged and compacted.
- Monitor memory and CPU usage after the update.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-119234.
| URL | Resource |
|---|---|
| https://github.com/meta/mvfst/commit/7e5cff58e8cbed87793141ceeca0a8a343c67c44 | |
| https://www.facebook.com/security/advisories/cve-2026-119234 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-119234 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-119234
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-119234 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-119234 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Nov. 11, 2026
Action Type Old Value New Value Added Description 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/119xxx/CVE-2026-119234.json">CVE-2026-119234</a> Added Reference https://github.com/meta/mvfst/commit/7e5cff58e8cbed87793141ceeca0a8a343c67c44 Added Reference https://www.facebook.com/security/advisories/cve-2026-119234