CVE-2026-91095

MEDIUM CVSS 3.1: 5.3 EPSS 0.25%
Updated Sep 30, 2026
Facebook
Parameter Value
CVSS 5.3 (MEDIUM)
Type CWE-416 (Use After Free)
Vendor Facebook
Public PoC No

In proxygen from v2024.10.28.00 until v2026.09.28.00, the HTTPTransaction::onWebTransportUniStream and HTTPTransaction::onWebTransportBidiStream APIs could return stream handles that the stream handler had already freed. HQSession then installed those handles as transport read callbacks, which could lead to use of freed memory.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
Low
Partial disruption

CVSS Vector v3.1

Weakness Type (CWE)

Vulnerable Products

facebook:proxygen