{"id":"CVE-2026-91095","title":"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","summary":"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 i…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","cwe":["CWE-416"],"vendor":"Facebook","product":"proxygen","affected":["proxygen >= v2024.10.28.00 < v2026.09.28.00"],"published":"2026-09-28","updated":"2026-09-30","sourceUpdated":"2026-09-30T20:17:36.470","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-91095","references":[{"url":"https://github.com/facebook/proxygen/commit/479eb5574195764e80e6cedebef669f6baa85083","label":"cve-assign@fb.com"},{"url":"https://www.facebook.com/security/advisories/cve-2026-91095","label":"cve-assign@fb.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91095.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-91095"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-91095"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-30T19:49:10.823542Z"},"epss":0.00247,"epssPercentile":0.15894,"scores":{"nvd":5.3,"vendor":7.5},"ingestedAt":"2026-09-28T21:20:54.787Z","slug":"CVE-2026-91095","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · updated 2026-09-29 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91095.json)","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":213911,"id":"CVE-2026-91095","ts":1790799885090,"field":"cvss","old":"7.5","new":"5.3"},{"seq":213910,"id":"CVE-2026-91095","ts":1790799885090,"field":"severity","old":"high","new":"medium"},{"seq":212295,"id":"CVE-2026-91095","ts":1790668139368,"field":"cvss","old":null,"new":"7.5"},{"seq":212294,"id":"CVE-2026-91095","ts":1790668139368,"field":"severity","old":"none","new":"high"}]}