{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64086", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.032Z", "datePublished": "2026-07-19T15:39:56.749Z", "dateUpdated": "2026-08-05T12:39:03.986Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:39:03.986Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus/adm1266) include PEC byte in pmbus_block_xfer read buffer\n\nadm1266_pmbus_block_xfer() sets up the read transaction with\n\n\t.buf = data->read_buf,\n\t.len = ADM1266_PMBUS_BLOCK_MAX + 2,\n\nbut read_buf in struct adm1266_data is declared as\n\n\tu8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1];\n\nFor a max-length block response (length byte = 255 + up to 1 PEC\nbyte), the i2c controller is told to write 257 bytes into a 256-byte\nbuffer, putting one byte past the end of read_buf. The same response\nalso makes the subsequent PEC compare\n\n\tif (crc != msgs[1].buf[msgs[1].buf[0] + 1])\n\nread a byte beyond the array.\n\nBump the read_buf declaration to ADM1266_PMBUS_BLOCK_MAX + 2 so the\nbuffer can hold the length byte, up to 255 payload bytes, and the PEC\nbyte the i2c_msg length already accounts for." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable code is only reached through local kernel interfaces (debugfs GPIO dump at /sys/kernel/debug/gpio and root-only nvmem blackbox reads), not through any network protocol handler. The ADM1266 sits on an on-board I2C bus on server BMC hardware.\nAC:L - An attacker who controls the I2C bus response (malicious device, compromised ADM1266 firmware, or bus interposition on the BMC) can reliably force a 255-byte block reply whenever a victim triggers the block-transfer path, causing the one-byte overflow on demand.\nPR:L - The gpio debugfs entry is world-readable (0444) if debugfs is mounted and traversable, which occurs on some embedded BMC images without strict permissions; between requiring full init-namespace root and that lower bar, the less privileged path is plausible on misconfigured systems.\nUI:N - Exploitation does not require victim interaction beyond the attacker (or a compromised daemon) programmatically reading debugfs or nvmem; no mount, click, or plug-in action by an end user is needed.\nS:U - Impact is confined to kernel memory corruption within the BMC/host kernel security boundary; this is not a VM escape, IOMMU bypass, or cross-authority sandbox breakout.\nC:H - The PEC validation performs an out-of-bounds read past read_buf, and the one-byte heap overflow can corrupt adjacent kernel objects in ways that enable further memory disclosure primitives.\nI:H - A one-byte, attacker-controlled out-of-bounds write past the end of read_buf into adjacent heap memory can corrupt slab metadata or neighboring objects and be developed into arbitrary write or code-execution primitives.\nA:H - Corrupting adjacent heap objects via the out-of-bounds write can cause kernel oops, panic, or hang on the BMC, denying management-plane availability for the managed server." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/hwmon/pmbus/adm1266.c" ], "versions": [ { "version": "407dc802a9c0809ca6a48de4b4c63305eb84ef56", "lessThan": "397d3f523bfff2f4e3dacf9b1339bd76dc207f78", "status": "affected", "versionType": "git" }, { "version": "407dc802a9c0809ca6a48de4b4c63305eb84ef56", "lessThan": "472744f69d25a2d5111ad62f1d62579dce2c13c8", "status": "affected", "versionType": "git" }, { "version": "407dc802a9c0809ca6a48de4b4c63305eb84ef56", "lessThan": "528a9f88e88502d0c2f2052a279415074cd83715", "status": "affected", "versionType": "git" }, { "version": "407dc802a9c0809ca6a48de4b4c63305eb84ef56", "lessThan": "d94ceb16e55b6d8019ab069e357c76ac42f0ffbc", "status": "affected", "versionType": "git" }, { "version": "407dc802a9c0809ca6a48de4b4c63305eb84ef56", "lessThan": "bd5be3fa5de6dbf61f1b3cec6b79c2c2f8065694", "status": "affected", "versionType": "git" }, { "version": "407dc802a9c0809ca6a48de4b4c63305eb84ef56", "lessThan": "2279c342d94eca225bf9f301c8806a05a1c81619", "status": "affected", "versionType": "git" }, { "version": "407dc802a9c0809ca6a48de4b4c63305eb84ef56", "lessThan": "a6c802145a8de0830bca803c6d415f7e9e683624", "status": "affected", "versionType": "git" }, { "version": "407dc802a9c0809ca6a48de4b4c63305eb84ef56", "lessThan": "487566cb1ccdf3756fdd7bf8d875e612ff3169bb", "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/hwmon/pmbus/adm1266.c" ], "versions": [ { "version": "5.10", "status": "affected" }, { "version": "0", "lessThan": "5.10", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.258", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.142", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.92", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.34", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.11", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "5.10", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.6.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.12.92" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.18.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "7.0.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/397d3f523bfff2f4e3dacf9b1339bd76dc207f78" }, { "url": "https://git.kernel.org/stable/c/472744f69d25a2d5111ad62f1d62579dce2c13c8" }, { "url": "https://git.kernel.org/stable/c/528a9f88e88502d0c2f2052a279415074cd83715" }, { "url": "https://git.kernel.org/stable/c/d94ceb16e55b6d8019ab069e357c76ac42f0ffbc" }, { "url": "https://git.kernel.org/stable/c/bd5be3fa5de6dbf61f1b3cec6b79c2c2f8065694" }, { "url": "https://git.kernel.org/stable/c/2279c342d94eca225bf9f301c8806a05a1c81619" }, { "url": "https://git.kernel.org/stable/c/a6c802145a8de0830bca803c6d415f7e9e683624" }, { "url": "https://git.kernel.org/stable/c/487566cb1ccdf3756fdd7bf8d875e612ff3169bb" } ], "title": "hwmon: (pmbus/adm1266) include PEC byte in pmbus_block_xfer read buffer", "x_generator": { "engine": "bippy-1.2.0" } } } }