{"id":"CVE-2026-45865","state":"PUBLISHED","title":"mctp i2c: initialise event handler read bytes","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmctp i2c: initialise event handler read bytes\n\nSet a 0xff value for i2c reads of an mctp-i2c device. Otherwise reads\nwill return \"val\" from the i2c bus driver. For i2c-aspeed and\ni2c-npcm7xx that is a stack uninitialised u8.\n\nTested with \"i2ctransfer -y 1 r10@0x34\" where 0x34 is a mctp-i2c\ninstance, now it returns all 0xff.","publishedAt":"2026-05-27T12:15:45.082Z","updatedAt":"2026-05-27T12:15:45.082Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f5b8abf9fc3dacd7529d363e26fe8230935d65f8","status":"affected","lessThan":"93e01e837e105299f1c259ef71f6e1ec4fe806e3","versionType":"git"},{"version":"f5b8abf9fc3dacd7529d363e26fe8230935d65f8","status":"affected","lessThan":"11f83253244060b5de5eac787f61ae3f3e559d01","versionType":"git"},{"version":"f5b8abf9fc3dacd7529d363e26fe8230935d65f8","status":"affected","lessThan":"fa9861e5c8af7651dddfa8d490aaada17ae33b6c","versionType":"git"},{"version":"f5b8abf9fc3dacd7529d363e26fe8230935d65f8","status":"affected","lessThan":"6ff2ebfef75fbc57d937d8fbe738b967edf2d331","versionType":"git"},{"version":"f5b8abf9fc3dacd7529d363e26fe8230935d65f8","status":"affected","lessThan":"1eeedb310229bfee9dd4d992e5bba33fe1378a8f","versionType":"git"},{"version":"f5b8abf9fc3dacd7529d363e26fe8230935d65f8","status":"affected","lessThan":"2a14e91b6d76639dac70ea170f4384c1ee3cb48d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/mctp/mctp-i2c.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.18","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/mctp/mctp-i2c.c"]}],"references":["https://git.kernel.org/stable/c/93e01e837e105299f1c259ef71f6e1ec4fe806e3","https://git.kernel.org/stable/c/11f83253244060b5de5eac787f61ae3f3e559d01","https://git.kernel.org/stable/c/fa9861e5c8af7651dddfa8d490aaada17ae33b6c","https://git.kernel.org/stable/c/6ff2ebfef75fbc57d937d8fbe738b967edf2d331","https://git.kernel.org/stable/c/1eeedb310229bfee9dd4d992e5bba33fe1378a8f","https://git.kernel.org/stable/c/2a14e91b6d76639dac70ea170f4384c1ee3cb48d"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/45xxx/CVE-2026-45865.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45865","state":"PUBLISHED","datePublished":"2026-05-27T12:15:45.082Z","dateUpdated":"2026-05-27T12:15:45.082Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.080Z"},"containers":{"cna":{"title":"mctp i2c: initialise event handler read bytes","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmctp i2c: initialise event handler read bytes\n\nSet a 0xff value for i2c reads of an mctp-i2c device. Otherwise reads\nwill return \"val\" from the i2c bus driver. For i2c-aspeed and\ni2c-npcm7xx that is a stack uninitialised u8.\n\nTested with \"i2ctransfer -y 1 r10@0x34\" where 0x34 is a mctp-i2c\ninstance, now it returns all 0xff."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f5b8abf9fc3dacd7529d363e26fe8230935d65f8","status":"affected","lessThan":"93e01e837e105299f1c259ef71f6e1ec4fe806e3","versionType":"git"},{"version":"f5b8abf9fc3dacd7529d363e26fe8230935d65f8","status":"affected","lessThan":"11f83253244060b5de5eac787f61ae3f3e559d01","versionType":"git"},{"version":"f5b8abf9fc3dacd7529d363e26fe8230935d65f8","status":"affected","lessThan":"fa9861e5c8af7651dddfa8d490aaada17ae33b6c","versionType":"git"},{"version":"f5b8abf9fc3dacd7529d363e26fe8230935d65f8","status":"affected","lessThan":"6ff2ebfef75fbc57d937d8fbe738b967edf2d331","versionType":"git"},{"version":"f5b8abf9fc3dacd7529d363e26fe8230935d65f8","status":"affected","lessThan":"1eeedb310229bfee9dd4d992e5bba33fe1378a8f","versionType":"git"},{"version":"f5b8abf9fc3dacd7529d363e26fe8230935d65f8","status":"affected","lessThan":"2a14e91b6d76639dac70ea170f4384c1ee3cb48d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/mctp/mctp-i2c.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.18","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/mctp/mctp-i2c.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/93e01e837e105299f1c259ef71f6e1ec4fe806e3"},{"url":"https://git.kernel.org/stable/c/11f83253244060b5de5eac787f61ae3f3e559d01"},{"url":"https://git.kernel.org/stable/c/fa9861e5c8af7651dddfa8d490aaada17ae33b6c"},{"url":"https://git.kernel.org/stable/c/6ff2ebfef75fbc57d937d8fbe738b967edf2d331"},{"url":"https://git.kernel.org/stable/c/1eeedb310229bfee9dd4d992e5bba33fe1378a8f"},{"url":"https://git.kernel.org/stable/c/2a14e91b6d76639dac70ea170f4384c1ee3cb48d"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-27T12:15:45.082Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.1.165"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.6.128"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.12.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.18.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.19.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}