{"id":"CVE-2026-68279","state":"PUBLISHED","title":"drm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers\n\ndrm_dp_sideband_parse_remote_dpcd_read() reads num_bytes from the raw\nmessage and then unconditionally does:\n\n  memcpy(bytes, &raw->msg[idx], num_bytes);\n\nwithout checking that idx + num_bytes <= raw->curlen. raw->msg[] is\n256 bytes; if a malicious or misbehaving MST hub sets num_bytes larger\nthan the remaining payload, the memcpy reads past the received data\ninto whatever follows in raw->msg[].\n\ndrm_dp_sideband_parse_remote_i2c_read_ack() has the same flaw (noted\nwith a /* TODO check */ comment since the code was introduced).\n\nFix both functions by using a single combined check\n(idx + num_bytes > curlen) before each memcpy. Since num_bytes is u8,\nit is always >= 0, so this strictly subsumes the simpler idx > curlen\nform and no separate step is needed.\n\n[added missing fixes tag]","publishedAt":"2026-08-10T12:02:09.423Z","updatedAt":"2026-08-23T12:46:16.563Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"185de1d74e658e2edb723ba76fa61903f77d8a68","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"d7b9b1e33b4ed8c48d4db6e6e21c257ebbbb2586","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"c2fbda0fe0163c55ba3820ee6cea0c6b43622eda","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"22d9f7fc1aaabaf73d5f30e8b0c9aa814ecd6ed2","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"04d953f50d61e542e94a5977822cc53735f8c0ce","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"533d9e2bede4aeefdc2a0561d7071cfede95958f","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"e6ef5455b06cb4e5d181aabcd723791587c79f12","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"1a8f537f5a1eeac941f262fe73078d6b08ba83c0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/display/drm_dp_mst_topology.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.17","versionType":"semver"},{"version":"5.10.266","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.217","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/display/drm_dp_mst_topology.c"]}],"references":["https://git.kernel.org/stable/c/185de1d74e658e2edb723ba76fa61903f77d8a68","https://git.kernel.org/stable/c/d7b9b1e33b4ed8c48d4db6e6e21c257ebbbb2586","https://git.kernel.org/stable/c/c2fbda0fe0163c55ba3820ee6cea0c6b43622eda","https://git.kernel.org/stable/c/22d9f7fc1aaabaf73d5f30e8b0c9aa814ecd6ed2","https://git.kernel.org/stable/c/04d953f50d61e542e94a5977822cc53735f8c0ce","https://git.kernel.org/stable/c/533d9e2bede4aeefdc2a0561d7071cfede95958f","https://git.kernel.org/stable/c/e6ef5455b06cb4e5d181aabcd723791587c79f12","https://git.kernel.org/stable/c/1a8f537f5a1eeac941f262fe73078d6b08ba83c0"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68279.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68279","state":"PUBLISHED","datePublished":"2026-08-10T12:02:09.423Z","dateUpdated":"2026-08-23T12:46:16.563Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.379Z"},"containers":{"cna":{"title":"drm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers\n\ndrm_dp_sideband_parse_remote_dpcd_read() reads num_bytes from the raw\nmessage and then unconditionally does:\n\n  memcpy(bytes, &raw->msg[idx], num_bytes);\n\nwithout checking that idx + num_bytes <= raw->curlen. raw->msg[] is\n256 bytes; if a malicious or misbehaving MST hub sets num_bytes larger\nthan the remaining payload, the memcpy reads past the received data\ninto whatever follows in raw->msg[].\n\ndrm_dp_sideband_parse_remote_i2c_read_ack() has the same flaw (noted\nwith a /* TODO check */ comment since the code was introduced).\n\nFix both functions by using a single combined check\n(idx + num_bytes > curlen) before each memcpy. Since num_bytes is u8,\nit is always >= 0, so this strictly subsumes the simpler idx > curlen\nform and no separate step is needed.\n\n[added missing fixes tag]"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"185de1d74e658e2edb723ba76fa61903f77d8a68","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"d7b9b1e33b4ed8c48d4db6e6e21c257ebbbb2586","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"c2fbda0fe0163c55ba3820ee6cea0c6b43622eda","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"22d9f7fc1aaabaf73d5f30e8b0c9aa814ecd6ed2","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"04d953f50d61e542e94a5977822cc53735f8c0ce","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"533d9e2bede4aeefdc2a0561d7071cfede95958f","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"e6ef5455b06cb4e5d181aabcd723791587c79f12","versionType":"git"},{"version":"ad7f8a1f9ced7f049f9b66d588723f243a7034cd","status":"affected","lessThan":"1a8f537f5a1eeac941f262fe73078d6b08ba83c0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/display/drm_dp_mst_topology.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.17","versionType":"semver"},{"version":"5.10.266","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.217","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/display/drm_dp_mst_topology.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/185de1d74e658e2edb723ba76fa61903f77d8a68"},{"url":"https://git.kernel.org/stable/c/d7b9b1e33b4ed8c48d4db6e6e21c257ebbbb2586"},{"url":"https://git.kernel.org/stable/c/c2fbda0fe0163c55ba3820ee6cea0c6b43622eda"},{"url":"https://git.kernel.org/stable/c/22d9f7fc1aaabaf73d5f30e8b0c9aa814ecd6ed2"},{"url":"https://git.kernel.org/stable/c/04d953f50d61e542e94a5977822cc53735f8c0ce"},{"url":"https://git.kernel.org/stable/c/533d9e2bede4aeefdc2a0561d7071cfede95958f"},{"url":"https://git.kernel.org/stable/c/e6ef5455b06cb4e5d181aabcd723791587c79f12"},{"url":"https://git.kernel.org/stable/c/1a8f537f5a1eeac941f262fe73078d6b08ba83c0"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-23T12:46:16.563Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"5.10.266"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"5.15.217"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"6.6.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}