CVE-2026-91096
High
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.
SeverityHigh
CVSS7.5
Exploit probability—
ProductFacebook Proxygen
PublishedSep 28, 2026
First seenSep 28, 2026
Weakness typeCWE-416Use after free
How to fix
Update
- Facebook proxygenv2026.09.28.00 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Facebook proxygen | v2024.10.28.00 ≤ v < v2026.09.28.00 | v2026.09.28.00 |
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