{"id":"CVE-2026-72397","state":"PUBLISHED","title":"hwmon: (pmbus/core) honor vrm_version in pmbus_data2reg_vid()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus/core) honor vrm_version in pmbus_data2reg_vid()\n\npmbus_data2reg_vid() hardcoded the VR11 encoding regardless of the\nvrm_version configured by the driver, while pmbus_reg2data_vid()\nalready switched on it. Any driver that selects a non-VR11 VID mode\nand exposes a regulator (or hwmon vout setter) sent dangerously\nwrong codes to PMBUS_VOUT_COMMAND -- e.g. an nvidia195mv part asked\nfor 200 mV got the VR11 clamp to 500 mV encoded as 0xB2, which the\nchip interprets as 1080 mV.\n\nMirror pmbus_reg2data_vid() so writes round-trip with reads.","publishedAt":"2026-08-15T05:56:23.675Z","updatedAt":"2026-10-21T12:44:48.405Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"068c227056b9223fea1a759e08db2558d5cbb5ad","status":"affected","lessThan":"cd0e037130806d7714c356eccefac6e1b92dbc34","versionType":"git"},{"version":"068c227056b9223fea1a759e08db2558d5cbb5ad","status":"affected","lessThan":"125a5a4ad03c74ced4c2a55db45ef03505362ff9","versionType":"git"},{"version":"068c227056b9223fea1a759e08db2558d5cbb5ad","status":"affected","lessThan":"5bd0d47640395f8a8c34446b62d1781b88869dfa","versionType":"git"},{"version":"068c227056b9223fea1a759e08db2558d5cbb5ad","status":"affected","lessThan":"828cd614e2af053ca5e1d6da767bbd8a1b5cabfb","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hwmon/pmbus/pmbus_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.3","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"7.1.5","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/hwmon/pmbus/pmbus_core.c"]}],"references":["https://git.kernel.org/stable/c/cd0e037130806d7714c356eccefac6e1b92dbc34","https://git.kernel.org/stable/c/125a5a4ad03c74ced4c2a55db45ef03505362ff9","https://git.kernel.org/stable/c/5bd0d47640395f8a8c34446b62d1781b88869dfa","https://git.kernel.org/stable/c/828cd614e2af053ca5e1d6da767bbd8a1b5cabfb"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72397.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72397","state":"PUBLISHED","datePublished":"2026-08-15T05:56:23.675Z","dateUpdated":"2026-10-21T12:44:48.405Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.924Z"},"containers":{"cna":{"title":"hwmon: (pmbus/core) honor vrm_version in pmbus_data2reg_vid()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus/core) honor vrm_version in pmbus_data2reg_vid()\n\npmbus_data2reg_vid() hardcoded the VR11 encoding regardless of the\nvrm_version configured by the driver, while pmbus_reg2data_vid()\nalready switched on it. Any driver that selects a non-VR11 VID mode\nand exposes a regulator (or hwmon vout setter) sent dangerously\nwrong codes to PMBUS_VOUT_COMMAND -- e.g. an nvidia195mv part asked\nfor 200 mV got the VR11 clamp to 500 mV encoded as 0xB2, which the\nchip interprets as 1080 mV.\n\nMirror pmbus_reg2data_vid() so writes round-trip with reads."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"068c227056b9223fea1a759e08db2558d5cbb5ad","status":"affected","lessThan":"cd0e037130806d7714c356eccefac6e1b92dbc34","versionType":"git"},{"version":"068c227056b9223fea1a759e08db2558d5cbb5ad","status":"affected","lessThan":"125a5a4ad03c74ced4c2a55db45ef03505362ff9","versionType":"git"},{"version":"068c227056b9223fea1a759e08db2558d5cbb5ad","status":"affected","lessThan":"5bd0d47640395f8a8c34446b62d1781b88869dfa","versionType":"git"},{"version":"068c227056b9223fea1a759e08db2558d5cbb5ad","status":"affected","lessThan":"828cd614e2af053ca5e1d6da767bbd8a1b5cabfb","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hwmon/pmbus/pmbus_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.3","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"7.1.5","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/hwmon/pmbus/pmbus_core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/cd0e037130806d7714c356eccefac6e1b92dbc34"},{"url":"https://git.kernel.org/stable/c/125a5a4ad03c74ced4c2a55db45ef03505362ff9"},{"url":"https://git.kernel.org/stable/c/5bd0d47640395f8a8c34446b62d1781b88869dfa"},{"url":"https://git.kernel.org/stable/c/828cd614e2af053ca5e1d6da767bbd8a1b5cabfb"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is only reached from local host interfaces—writable hwmon sysfs attributes (pmbus_set_sensor) and the PMBus regulator set_voltage path (pmbus_regulator_set_voltage)—which encode values and issue I2C PMBUS_VOUT_COMMAND writes; there is no network, adjacent-radio, or direct physical-access entry point.\nAC:L - On systems with non-VR11 VID PMBus controllers (VR12/VR13/IMVP9/AMD/nvidia195mv), any voltage-setting write deterministically uses the wrong VR11 encoding with no race, timing window, or uncontrollable memory layout; the attacker fully controls the written millivolt value and can repeat the operation reliably.\nPR:L - Writable hwmon limit attributes are exposed as mode 0644 with no capability check in pmbus_set_sensor, so a local uid-0 context (including user-namespace root or container root with /sys access) can drive the bad encoding; regulator consumers can also be influenced from ordinary local workloads on affected server/GPU platforms.\nUI:N - Exploitation requires only the attacker (or attacker-controlled software) to write hwmon voltage limits or invoke regulator voltage changes; no separate victim interaction such as plugging hardware or approving a prompt is needed.\nS:U - Impact is confined to misprogramming PMBus voltage rails on the same host kernel authority; it does not cross VM, IOMMU, or sandbox boundaries and is not a guest-to-host escape.\nC:N - This is a write-side VID encoding logic error, not kernel memory corruption; reads use the correct pmbus_reg2data_vid path and the flaw does not disclose kernel pointers, arbitrary memory, or other confidential data.\nI:H - Incorrect VID-to-register conversion sends dangerously wrong PMBUS_VOUT_COMMAND values to hardware (e.g., 200 mV requested on nvidia195mv becomes 1080 mV applied), corrupting critical CPU/GPU/board power-rail configuration and potentially causing permanent hardware damage.\nA:H - Severe over- or under-voltage on core power rails can trigger immediate hardware protection shutdowns, system hangs/resets, and sustained denial of service on data-center, HPC, and GPU server deployments using affected PMBus VRM controllers."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-21T12:44:48.405Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-72397","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T18:48:52.527560Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T18:55:21.400Z"}}]}}}