SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-84894

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.

HIGH 7.5EPSS 0.26%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
0.26% probability · 17th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-416
Source
cve-assign@fb.com
EPSS trend
0%3%5%29 September 2026: 0.14%26 October 2026: 0.26%29 September 202626 October 2026

EPSS moved from 0.1% on 29 September 2026 to 0.3% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.