CVE-2026-119234

Published Nov 11, 2026 CVSS n/a EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
Title Denial of Service via Out-of-Order Stream Fragmentation in Facebook mvfst
Weaknesses CWE-399
CWE-770
Type Values Removed Values Added
First Time appeared Facebook
Facebook mvfst
Vendors & Products Facebook
Facebook mvfst
Type Values Removed Values Added
Title Denial of Service via Out-of-Order Stream Fragmentation in Facebook mvfst
Weaknesses CWE-399
CWE-770
Type Values Removed Values 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.
References
Weaknesses

No weakness.

Sources

Status
PUBLISHED
Assigner
Meta
Published
Updated
Nov 11, 2026, 4:54 PM
Reserved
Oct 29, 2026, 5:01 PM
Status
Awaiting Analysis
Published
Nov 11, 2026, 5:17 PM
Modified
Nov 12, 2026, 8:04 PM