{"id":"CVE-2026-91948","summary":"FreeRDP before 3.31.0 Out-of-bounds Write via SHOW_PROTOCOL","details":"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 cause buffer underflow and corrupt heap memory including live pointers, potentially enabling code execution.","aliases":["GHSA-9jcm-x588-gh26"],"modified":"2026-09-17T03:47:20.689813174Z","published":"2026-09-15T15:18:06.465Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-191"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/91xxx/CVE-2026-91948.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/91xxx/CVE-2026-91948.json"},{"type":"ADVISORY","url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9jcm-x588-gh26"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-91948"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/freerdp-before-3.31.0-out-of-bounds-write-via-show-protocol"},{"type":"FIX","url":"https://github.com/FreeRDP/FreeRDP/commit/40d9202cd95551600c07437ce6bd5ecd7d31e57b"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/freerdp/freerdp","events":[{"introduced":"5370fb26fbf034ecd11d3026b6ad639b5fff493f"},{"fixed":"aa8650b300aa4cabd85d9c72b431301509b9043f"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"3.28.0"},{"fixed":"3.31.0"}]}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-91948.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}