{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-81007","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-26T14:34:25.812Z","datePublished":"2026-09-11T19:42:58.751Z","dateUpdated":"2026-09-14T11:59:40.685Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-14T11:59:40.685Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipmi: ipmb: validate write message length\n\nipmb_write() read message fields before validating the length byte.\n\nA zero or short write can read uninitialized stack bytes.\n\nA length smaller than the SMBus header underflows the block write length.\n\nRequire a non-empty buffer and the minimum IPMB request length.\n\nAlso require the length byte plus payload before parsing the message."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - ipmb_write() is the miscdevice write handler for /dev/ipmb-N and is reached only via a local write(2) on that character device. The I2C slave callback queues inbound IPMB requests for read() and does not enter this path.\nAC:L - A single write of count 0, or a 1-byte write with length field 0, bypasses the old count<msg[0] check and underflows the I2C/SMBus length. The attacker fully controls the buffer; no race or uninfluenced memory layout is required.\nPR:L - Neither ipmb_write() nor misc_open() performs a capability check; access is only DAC on /dev/ipmb-N. BMC and satellite-MC deployments (OpenBMC ipmbbridge, OpenIPMI) commonly grant this node to a non-root management or service account rather than requiring init-namespace root.\nUI:N - The attacker triggers the bug entirely with their own write(2) to an already-present /dev/ipmb-N node. No other user must open a file, mount a filesystem, or otherwise interact.\nS:U - The out-of-bounds stack read and resulting kernel oops remain inside the same host kernel security authority. IPMB/I2C is an in-chassis management bus, not a VM, IOMMU, or sandbox boundary crossing.\nC:H - On i2c-protocol devices (usual OpenBMC/Aspeed DT), a zero length byte promotes to i2c_msg.len 65535, so i2c_transfer/DMA helpers read tens of kilobytes past the 240-byte stack buffer, disclosing kernel stack contents onto the IPMB bus.\nI:N - The defect is an out-of-bounds read of a stack buffer used as an I2C write payload. It does not write kernel memory, corrupt heap objects, or yield a control-flow or arbitrary-write primitive.\nA:H - The 65535-byte stack over-read walks off the kernel stack. Aspeed I2C (typical OpenBMC IPMB adapter) has no max_write_len quirk, so the transfer or memcpy hits the VMAP_STACK guard page and oopses the kernel."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/char/ipmi/ipmb_dev_int.c"],"versions":[{"version":"51bd6f291583684f495ea498984dfc22049d7fd2","lessThan":"8990c7f6bfc1e7689b7012a7d4d0efb9f07a9c89","status":"affected","versionType":"git"},{"version":"51bd6f291583684f495ea498984dfc22049d7fd2","lessThan":"94f8d20153e348c79bc14dc25f873470518892da","status":"affected","versionType":"git"},{"version":"51bd6f291583684f495ea498984dfc22049d7fd2","lessThan":"e527cd4e80066e1ed070fdc7c705bde340cdcc62","status":"affected","versionType":"git"},{"version":"51bd6f291583684f495ea498984dfc22049d7fd2","lessThan":"7d66d54b974cff0a959e188af844d2d110422767","status":"affected","versionType":"git"},{"version":"51bd6f291583684f495ea498984dfc22049d7fd2","lessThan":"60939bcda6f3f104ef456fdbf3cc5733c0720fb1","status":"affected","versionType":"git"},{"version":"51bd6f291583684f495ea498984dfc22049d7fd2","lessThan":"5719431ca2b5fa26560bb38f6202f8b97fa3bbb0","status":"affected","versionType":"git"},{"version":"51bd6f291583684f495ea498984dfc22049d7fd2","lessThan":"a84c6e3d188f2c6e674910929eb790634299d6d5","status":"affected","versionType":"git"},{"version":"51bd6f291583684f495ea498984dfc22049d7fd2","lessThan":"53637506884dbd5c91a89b1a3547d99d80f8ed2c","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/char/ipmi/ipmb_dev_int.c"],"versions":[{"version":"5.3","status":"affected"},{"version":"0","lessThan":"5.3","status":"unaffected","versionType":"semver"},{"version":"5.10.270","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.221","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.188","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.157","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.109","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.50","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.4","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"7.3-rc1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/8990c7f6bfc1e7689b7012a7d4d0efb9f07a9c89"},{"url":"https://git.kernel.org/stable/c/94f8d20153e348c79bc14dc25f873470518892da"},{"url":"https://git.kernel.org/stable/c/e527cd4e80066e1ed070fdc7c705bde340cdcc62"},{"url":"https://git.kernel.org/stable/c/7d66d54b974cff0a959e188af844d2d110422767"},{"url":"https://git.kernel.org/stable/c/60939bcda6f3f104ef456fdbf3cc5733c0720fb1"},{"url":"https://git.kernel.org/stable/c/5719431ca2b5fa26560bb38f6202f8b97fa3bbb0"},{"url":"https://git.kernel.org/stable/c/a84c6e3d188f2c6e674910929eb790634299d6d5"},{"url":"https://git.kernel.org/stable/c/53637506884dbd5c91a89b1a3547d99d80f8ed2c"}],"title":"ipmi: ipmb: validate write message length","x_generator":{"engine":"bippy-1.2.0"}}}}