{"id":"CVE-2026-91948","title":"FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in server-side static virtual channel handling when CHANNEL_OPTION_SHOW_PROTOCOL is enabled","summary":"FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in server-side static virtual channel handling when CHANNEL_OPTION_SHOW_PROTOCOL is enabled. Authenticated clients can queue oversized channel messages that caus…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-191","CWE-124"],"vendor":"FreeRDP","product":"FreeRDP","affected":["FreeRDP >= 3.28.0 < 3.31.0"],"published":"2026-09-15","updated":"2026-09-17","sourceUpdated":"2026-09-17T12:18:29.793","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-91948","references":[{"url":"https://github.com/FreeRDP/FreeRDP/commit/40d9202cd95551600c07437ce6bd5ecd7d31e57b","label":"disclosure@vulncheck.com"},{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9jcm-x588-gh26","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/freerdp-before-3.31.0-out-of-bounds-write-via-show-protocol","label":"disclosure@vulncheck.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91948.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-91948"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2533904"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-91948"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-91948"}],"tags":["nvd","cve.org","exploit-available","csaf","vex","red-hat"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-09-16T03:56:31.656578Z"},"epss":0.00649,"epssPercentile":0.49701,"exploitAvailable":true,"ingestedAt":"2026-09-15T15:39:12.921Z","slug":"CVE-2026-91948","body":"## Overview\n\nFreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in server-side static virtual channel handling when CHANNEL_OPTION_SHOW_PROTOCOL is enabled. Authenticated clients can queue oversized channel messages that cause buffer underflow and corrupt heap memory including live pointers, potentially enabling code execution.\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** · Important · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91948.json)","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":204276,"id":"CVE-2026-91948","ts":1789490443072,"field":"exploit_available","old":"false","new":"true"}]}