Session Management Flaw in Proxygen Affecting Facebook's WebTransport Implementation
CVE-2026-91096

7.5HIGH

Key Information:

Vendor

Facebook

Status
Proxygen
Vendor
CVE Published:
28 September 2026

What is CVE-2026-91096?

A flaw in the Proxygen's WebTransport implementation allows for the failure to unregister read callbacks for streams that are no longer active before they are destroyed. This oversight can lead to scenarios where freed read callbacks might still be invoked by the transport mechanism, potentially resulting in unexpected behavior or crashes.

Affected Version(s)

proxygen v2024.10.28.00

References

https://www.facebook.com/security/advisories/cve-2026-91096
x_refsource_CONFIRM
https://github.com/facebook/proxygen/commit/479eb55741957...
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.