High severity · published Sep 28, 2026
CVE-2026-91096
In proxygen from v2024.10.28.00 until v2026.09.28.00, WebTransportImpl::terminateSessionStreams (WebTransportImpl::destroy in releases before v2025.08.18.00) failed to unregister…
7.5
CVSS
0.3%
EPSS
No
On KEV
Description
In proxygen from v2024.10.28.00 until v2026.09.28.00, WebTransportImpl::terminateSessionStreams (WebTransportImpl::destroy in releases before v2025.08.18.00) failed to unregister read callbacks for streams that were no longer open before destroying them. The transport could then invoke a read callback that had been freed.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 17% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PR
proxygen · Facebook
v2024.10.28.00 before v2026.09.28.00 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91096
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-91096
x_refsource_CONFIRM
https://www.facebook.com/security/advisories/cve-2026-91096
x_refsource_MISC
https://github.com/facebook/proxygen/commit/479eb5574195764e80e6cedebef669f6baa85083
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