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.

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History

Thu, 12 Nov 2026 12:00:00 +0000

Type Values Removed Values Added
Title Denial of Service via Out-of-Order Stream Fragmentation in Facebook mvfst
Weaknesses CWE-399
CWE-770

Wed, 11 Nov 2026 17:00:00 +0000

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.
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cve-icon MITRE

Status: PUBLISHED

Assigner: Meta

Published:

Updated: 2026-11-11T16:54:48.304Z

Reserved: 2026-10-29T17:01:32.523Z

Link: CVE-2026-119234

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-11-11T17:17:16.543

Modified: 2026-11-11T17:17:16.543

Link: CVE-2026-119234

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-12T11:45:02Z

Weaknesses