CVE-2026-91095
Proxygen Use-After-Free Vulnerability
Description
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.
INFO
Published Date :
Sept. 28, 2026, 9:17 p.m.
Last Modified :
Sept. 28, 2026, 9:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Solution
- Update Proxygen to a version that addresses the vulnerability.
- Verify the installation of the updated Proxygen version.
- Apply necessary security patches for Proxygen.
- Review Proxygen's stream handling logic.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-91095.
| URL | Resource |
|---|---|
| https://github.com/facebook/proxygen/commit/479eb5574195764e80e6cedebef669f6baa85083 | |
| https://www.facebook.com/security/advisories/cve-2026-91095 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-91095 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-91095
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-91095 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-91095 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 28, 2026
Action Type Old Value New Value Added Description 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/91xxx/CVE-2026-91095.json">CVE-2026-91095</a> Added Reference https://github.com/facebook/proxygen/commit/479eb5574195764e80e6cedebef669f6baa85083 Added Reference https://www.facebook.com/security/advisories/cve-2026-91095