{"id":"CVE-2026-55191","summary":"FreeRDP: Heap-buffer-overflow write in AVC444 YUV buffer allocation","details":"FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP clients that negotiate RDPGFX AVC444 with an H.264 decoder backend calculate the intermediate YUV444 allocation size in libfreerdp/codec/h264.c with 32-bit multiplication in avc444_ensure_buffer. A malicious RDP server can supply surface dimensions for which piDstStride multiplied by padDstHeight wraps to a small nonzero value, causing winpr_aligned_recalloc to allocate an undersized buffer before YUV420CombineToYUV444 writes using the actual stride and rectangle dimensions. This can cause a client crash and may permit code execution through attacker-influenced heap corruption. This issue is fixed in version 3.27.0.","aliases":["GHSA-vx73-w5q6-7jqr"],"modified":"2026-08-21T09:09:36.135455Z","published":"2026-08-19T17:44:52.392Z","related":["openSUSE-SU-2026:11065-1"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-122","CWE-190"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55191.json"},"references":[{"type":"WEB","url":"https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55191.json"},{"type":"ADVISORY","url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vx73-w5q6-7jqr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55191"},{"type":"FIX","url":"https://github.com/FreeRDP/FreeRDP/commit/97f40b9e766af375f4e41ac6a3f4397d708d249c"},{"type":"FIX","url":"https://github.com/FreeRDP/FreeRDP/pull/12873"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/freerdp/freerdp","events":[{"introduced":"0"},{"fixed":"97f40b9e766af375f4e41ac6a3f4397d708d249c"},{"fixed":"4f72b0979892352ff501e84d99832dc3bdc86a53"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"3.27.0"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["3.5.1","3.5.0","3.4.0","3.3.0","3.2.0","3.1.0","3.0.0","3.0.0-rc0","3.0.0-beta4","3.0.0-beta3","3.0.0-beta2","3.0.0-beta1","2.0.0","2.0.0-rc4","2.0.0-rc3","2.0.0-rc2","2.0.0-rc1","2.0.0-rc0","2.0.0-beta1+android11","2.0.0-beta1+android10","1.2.0-beta1+android9","1.2.0-beta1+android7","1.1.0-beta+2013071101","1.1.0-beta1+ios4","1.1.0-beta1+android5","1.1.0-beta1+android4","1.1.0-beta1+ios3","1.1.0-beta1+ios2","1.1.0-beta1+android3","1.1.0-beta1+android2","1.1.0-beta1+ios1","1.1.0-beta1","1.0.1","1.0.0","1.0-beta5","1.0-beta4","1.0-beta2","1.0-beta1"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-55191.json","vanir_signatures_modified":"2026-08-21T09:09:36Z","vanir_signatures":[{"id":"CVE-2026-55191-3b9508c3","signature_type":"Line","signature_version":"v1","source":"https://github.com/freerdp/freerdp/commit/97f40b9e766af375f4e41ac6a3f4397d708d249c","target":{"file":"libfreerdp/codec/h264.c"},"deprecated":false,"digest":{"line_hashes":["48174095235466160751121575708509728262","11144820776453550293254840977539219724","274401937115262867876596987545089614917","186272877945233000668693540578688413252","187565802453358020320230546053045453683","33817876480808945754884006534388078729","277059941125427303465452712062411898515","115157482681376152684946011057980634619","321490431307320095629976707404843296055","224435050257559175890767996891601908376"],"threshold":0.9}},{"deprecated":false,"digest":{"function_hash":"57696007405446287005638493369776229418","length":1302},"id":"CVE-2026-55191-596acca0","signature_type":"Function","signature_version":"v1","source":"https://github.com/freerdp/freerdp/commit/97f40b9e766af375f4e41ac6a3f4397d708d249c","target":{"file":"libfreerdp/codec/h264.c","function":"avc444_ensure_buffer"}}]}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}