Vulnerability · Published Sep 28, 2026 · Assigned by Meta
CVE-2026-84895
High 7.3
In plain English
A high-severity use-after-free in proxygen from Facebook. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities).
Severity (CVSS 3.1)7.3High
Exploit odds (30 days)0.2%top 90.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
In proxygen from v2026.04.06.00 until v2026.09.28.00, QuicWtSession::closeSession accesses its member fields after calling the base QuicWtSessionBase::closeSession method. The base method notifies the session handler, which may release the last reference to the session and destroy it.
Affected products (as reported)
Weakness: CWE-416 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
References
- https://www.facebook.com/security/advisories/cve-2026-84895 x_refsource_CONFIRM
- https://github.com/facebook/proxygen/commit/479eb5574195764e80e6cedebef669f6baa85083 x_refsource_MISC