{"id":"CVE-2026-55191","state":"PUBLISHED","title":"FreeRDP: Heap-buffer-overflow write in AVC444 YUV buffer allocation","description":"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.","publishedAt":"2026-08-19T17:44:52.392Z","updatedAt":"2026-08-19T18:17:07.147Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"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","source":"GitHub_M"},"assigner":"GitHub_M","products":["FreeRDP FreeRDP"],"affected":[{"vendor":"FreeRDP","product":"FreeRDP","versions":[{"version":"< 3.27.0","status":"affected"}]}],"references":["https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vx73-w5q6-7jqr","https://github.com/FreeRDP/FreeRDP/pull/12873","https://github.com/FreeRDP/FreeRDP/commit/97f40b9e766af375f4e41ac6a3f4397d708d249c","https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0"],"weaknesses":["CWE-122","CWE-190"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55191.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55191","state":"PUBLISHED","datePublished":"2026-08-19T17:44:52.392Z","dateUpdated":"2026-08-19T18:17:07.147Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T15:20:43.086Z"},"containers":{"cna":{"title":"FreeRDP: Heap-buffer-overflow write in AVC444 YUV buffer allocation","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"FreeRDP","product":"FreeRDP","versions":[{"version":"< 3.27.0","status":"affected"}]}],"references":[{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vx73-w5q6-7jqr","name":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vx73-w5q6-7jqr","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/FreeRDP/FreeRDP/pull/12873","name":"https://github.com/FreeRDP/FreeRDP/pull/12873","tags":["x_refsource_MISC"]},{"url":"https://github.com/FreeRDP/FreeRDP/commit/97f40b9e766af375f4e41ac6a3f4397d708d249c","name":"https://github.com/FreeRDP/FreeRDP/commit/97f40b9e766af375f4e41ac6a3f4397d708d249c","tags":["x_refsource_MISC"]},{"url":"https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0","name":"https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.7,"baseSeverity":"HIGH","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-122","lang":"en","description":"CWE-122: Heap-based Buffer Overflow","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-190","lang":"en","description":"CWE-190: Integer Overflow or Wraparound","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-19T17:44:52.392Z"},"source":{"advisory":"GHSA-vx73-w5q6-7jqr","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vx73-w5q6-7jqr","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-19T18:15:35.235601Z","id":"CVE-2026-55191","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-19T18:17:07.147Z"}}]}}}