{"id":"CVE-2026-67298","state":"PUBLISHED","title":"FreeRDP 3.28.0 Heap Buffer Overflow via RAIL orderLength Underflow","description":"FreeRDP versions 3.28.0 and earlier contain a heap buffer overflow in the server-side RAIL channel handler (rail_server_handle_messages() in channels/rail/server/rail_main.c). When processing a RAIL PDU header, the code subtracts RAIL_PDU_HEADER_LENGTH from the peer-controlled orderLength field without first verifying orderLength is at least the header length. For orderLength values 0..3 this causes an unsigned integer underflow to a very large size, which bypasses the Stream_EnsureRemainingCapacity() capacity check (due to pointer arithmetic wraparound) and is then passed to WTSVirtualChannelRead(), resulting in an out-of-bounds heap write. A malicious or compromised RDP client can exploit this to corrupt the heap and crash the server. Fixed in FreeRDP 3.29.0.","publishedAt":"2026-08-01T12:22:18.323Z","updatedAt":"2026-08-03T19:50:59.750Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["FreeRDP FreeRDP"],"affected":[{"vendor":"FreeRDP","product":"FreeRDP","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.29.0","versionType":"semver"},{"version":"3.29.0","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qmvw-52ph-q5pv","https://github.com/FreeRDP/FreeRDP/commit/5370fb26fbf034ecd11d3026b6ad639b5fff493f","https://github.com/FreeRDP/FreeRDP/commit/46848765f2a1134f8652f8760eefb5e85d64a9b8","https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-via-rail-orderlength-underflow","https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-5wr6-8m8j-3h7f"],"weaknesses":["CWE-191"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/67xxx/CVE-2026-67298.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-67298","state":"PUBLISHED","datePublished":"2026-08-01T12:22:18.323Z","dateUpdated":"2026-08-03T19:50:59.750Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-07-29T13:04:41.947Z"},"containers":{"cna":{"title":"FreeRDP 3.28.0 Heap Buffer Overflow via RAIL orderLength Underflow","descriptions":[{"lang":"en","value":"FreeRDP versions 3.28.0 and earlier contain a heap buffer overflow in the server-side RAIL channel handler (rail_server_handle_messages() in channels/rail/server/rail_main.c). When processing a RAIL PDU header, the code subtracts RAIL_PDU_HEADER_LENGTH from the peer-controlled orderLength field without first verifying orderLength is at least the header length. For orderLength values 0..3 this causes an unsigned integer underflow to a very large size, which bypasses the Stream_EnsureRemainingCapacity() capacity check (due to pointer arithmetic wraparound) and is then passed to WTSVirtualChannelRead(), resulting in an out-of-bounds heap write. A malicious or compromised RDP client can exploit this to corrupt the heap and crash the server. Fixed in FreeRDP 3.29.0."}],"affected":[{"vendor":"FreeRDP","product":"FreeRDP","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.29.0","versionType":"semver"},{"version":"3.29.0","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qmvw-52ph-q5pv","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-qmvw-52ph-q5pv)"},{"url":"https://github.com/FreeRDP/FreeRDP/commit/5370fb26fbf034ecd11d3026b6ad639b5fff493f","tags":["patch"],"name":"Patch Commit"},{"url":"https://github.com/FreeRDP/FreeRDP/commit/46848765f2a1134f8652f8760eefb5e85d64a9b8","tags":["patch"],"name":"Patch Commit"},{"url":"https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-via-rail-orderlength-underflow","name":"VulnCheck Advisory: FreeRDP 3.28.0 Heap Buffer Overflow via RAIL orderLength Underflow","tags":["third-party-advisory"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":8.7,"baseSeverity":"HIGH","exploitMaturity":"NOT_DEFINED","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS"},{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-191","lang":"en","description":"Integer Underflow (Wrap or Wraparound)","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-08-01T12:22:18.323Z"},"datePublic":"2026-07-15T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*","versionEndExcluding":"3.29.0"}]}]}],"credits":[{"lang":"en","value":"1121984919","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-5wr6-8m8j-3h7f","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-03T19:50:25.787082Z","id":"CVE-2026-67298","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-03T19:50:59.750Z"}}]}}}