CVE-2026-84894

Use‑After‑Free in moxygen Data Stream Read Loop Causes Service Crash

Published Sep 28, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
In moxygen before commit 004123dd24c3, MoQSession::dataStreamReadLoop keeps using a stream read handle after reading a FIN, which invalidates the handle under proxygen's WebTransport API. A remote peer can trigger the stale use by opening a data stream that names an unknown track alias and carries the FIN in the same write.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
Title Use‑After‑Free in moxygen Data Stream Read Loop Causes Service Crash
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Weaknesses CWE-416
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}

Type Values Removed Values Added
First Time appeared Meta Platforms Inc
Meta Platforms Inc moxygen
Vendors & Products Meta Platforms Inc
Meta Platforms Inc moxygen
Type Values Removed Values Added
Description In moxygen before commit 004123dd24c3, MoQSession::dataStreamReadLoop keeps using a stream read handle after reading a FIN, which invalidates the handle under proxygen's WebTransport API. A remote peer can trigger the stale use by opening a data stream that names an unknown track alias and carries the FIN in the same write.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Meta
Published
Updated
Sep 30, 2026, 3:05 PM
Reserved
Sep 2, 2026, 2:52 PM
Status
Deferred
Published
Sep 28, 2026, 7:16 PM
Modified
Sep 30, 2026, 7:57 PM