{"api_version":"1","generated_at":"2026-09-14T05:55:46+00:00","cve":"CVE-2026-80931","urls":{"html":"https://cve.report/CVE-2026-80931","api":"https://cve.report/api/cve/CVE-2026-80931.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80931","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80931"},"summary":{"title":"w1: ds28e17: reject an oversize length on an I2C block read","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nw1: ds28e17: reject an oversize length on an I2C block read\n\nw1_f19_i2c_master_transfer() is the master_xfer for the DS28E17 1-Wire\nto I2C bridge. On an I2C_M_RECV_LEN read, it takes the length from the\ndevice. The downstream slave puts a length byte in buf[0]. The driver\nthen reads that many bytes into buf[1] with w1_f19_i2c_read().\n\nbuf[0] is controlled by the device and can be 0 to 255.\nw1_f19_i2c_read() only rejects a zero count. The caller buffer is\nI2C_SMBUS_BLOCK_MAX + 2, so 34 bytes. A length above 32 makes the read\nrun past it, up to about 222 bytes out of bounds.\n\nThe SMBus core does check buf[0] against I2C_SMBUS_BLOCK_MAX. That\ncheck runs after master_xfer returns. By then the write is already\ndone. i2c-algo-bit rejects an oversize length before it copies, and\nreturns -EPROTO.\n\nReject a length above I2C_SMBUS_BLOCK_MAX at both RECV_LEN sites, the\nsame way i2c-algo-bit does.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:18:56","updated_at":"2026-09-13 07:17:00"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"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","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/169ae5e65e5aaf213b6a578f6478a9fd2e523606","name":"https://git.kernel.org/stable/c/169ae5e65e5aaf213b6a578f6478a9fd2e523606","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/cb55c5da9828f77db2a2701316949d4de1e9b773","name":"https://git.kernel.org/stable/c/cb55c5da9828f77db2a2701316949d4de1e9b773","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6df05f630c84a109736642362e452089886f9974","name":"https://git.kernel.org/stable/c/6df05f630c84a109736642362e452089886f9974","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ae0c79a8527044e54d81fd5a3b49ce6177633758","name":"https://git.kernel.org/stable/c/ae0c79a8527044e54d81fd5a3b49ce6177633758","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80931","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80931","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ebc4768ac4971eab4b570e733e47ac9dfd0e4175 cb55c5da9828f77db2a2701316949d4de1e9b773 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ebc4768ac4971eab4b570e733e47ac9dfd0e4175 ae0c79a8527044e54d81fd5a3b49ce6177633758 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ebc4768ac4971eab4b570e733e47ac9dfd0e4175 6df05f630c84a109736642362e452089886f9974 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ebc4768ac4971eab4b570e733e47ac9dfd0e4175 169ae5e65e5aaf213b6a578f6478a9fd2e523606 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.15","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.15 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.109 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.50 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"80931","cve":"CVE-2026-80931","epss":"0.001280000","percentile":"0.028190000","score_date":"2026-09-13","updated_at":"2026-09-14 00:18:01"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/w1/slaves/w1_ds28e17.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"cb55c5da9828f77db2a2701316949d4de1e9b773","status":"affected","version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","versionType":"git"},{"lessThan":"ae0c79a8527044e54d81fd5a3b49ce6177633758","status":"affected","version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","versionType":"git"},{"lessThan":"6df05f630c84a109736642362e452089886f9974","status":"affected","version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","versionType":"git"},{"lessThan":"169ae5e65e5aaf213b6a578f6478a9fd2e523606","status":"affected","version":"ebc4768ac4971eab4b570e733e47ac9dfd0e4175","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/w1/slaves/w1_ds28e17.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.15"},{"lessThan":"4.15","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.109","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.50","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.109","versionStartIncluding":"4.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.50","versionStartIncluding":"4.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"4.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"4.15","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nw1: ds28e17: reject an oversize length on an I2C block read\n\nw1_f19_i2c_master_transfer() is the master_xfer for the DS28E17 1-Wire\nto I2C bridge. On an I2C_M_RECV_LEN read, it takes the length from the\ndevice. The downstream slave puts a length byte in buf[0]. The driver\nthen reads that many bytes into buf[1] with w1_f19_i2c_read().\n\nbuf[0] is controlled by the device and can be 0 to 255.\nw1_f19_i2c_read() only rejects a zero count. The caller buffer is\nI2C_SMBUS_BLOCK_MAX + 2, so 34 bytes. A length above 32 makes the read\nrun past it, up to about 222 bytes out of bounds.\n\nThe SMBus core does check buf[0] against I2C_SMBUS_BLOCK_MAX. That\ncheck runs after master_xfer returns. By then the write is already\ndone. i2c-algo-bit rejects an oversize length before it copies, and\nreturns -EPROTO.\n\nReject a length above I2C_SMBUS_BLOCK_MAX at both RECV_LEN sites, the\nsame way i2c-algo-bit does."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The overflow is reached from local userspace via /dev/i2c-* I2C_SMBUS or I2C_RDWR ioctls into w1_f19_i2c_master_transfer() on the DS28E17-created I2C adapter; i2c-dev does not require advertised I2C_FUNC_SMBUS_READ_BLOCK_DATA. There is no network path; the 1-Wire-to-I2C bridge being present is a deployment precondition.\nAC:L - A single I2C_M_RECV_LEN block read uses the downstream slave's first data byte as the extra length with no cap, then w1_f19_i2c_read() copies that many bytes. The attacker chooses the ioctl and target address; a responding slave returning >32 (or data the attacker just wrote) overflows reliably, with no race or uncontrolled layout.\nPR:L - i2cdev_open() has no capability check; reachability depends only on /dev/i2c-* permissions, commonly 0660 root:i2c on embedded and industrial systems. That is unprivileged local access, not real init-namespace root.\nUI:N - The attacker triggers the bug with their own open/ioctl sequence on an already-present DS28E17 I2C adapter node. No victim action such as plugging in a device or mounting a filesystem is required.\nS:U - Impact is ordinary host-kernel stack or heap corruption of the SMBus/i2c-dev transfer buffer within the same kernel authority. It does not cross a VM, IOMMU, or other separate security boundary.\nC:H - A device-supplied length up to 255 causes an out-of-bounds write of about 222 bytes past the 34-byte I2C_SMBUS_BLOCK_MAX+2 buffer into adjacent kernel stack or heap. That memory corruption is defensibly leveraged for kernel information disclosure.\nI:H - Slave-controlled bytes are written past the end of the kernel transfer buffer, producing a substantial out-of-bounds kernel write. Such corruption is exploitable for arbitrary memory modification or control-flow hijacking.\nA:H - The out-of-bounds kernel write can corrupt heap or stack state and cause an oops, panic, or hang. The attacker can repeat the local ioctl to deny service."}]}],"providerMetadata":{"dateUpdated":"2026-09-13T06:28:11.350Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/cb55c5da9828f77db2a2701316949d4de1e9b773"},{"url":"https://git.kernel.org/stable/c/ae0c79a8527044e54d81fd5a3b49ce6177633758"},{"url":"https://git.kernel.org/stable/c/6df05f630c84a109736642362e452089886f9974"},{"url":"https://git.kernel.org/stable/c/169ae5e65e5aaf213b6a578f6478a9fd2e523606"}],"title":"w1: ds28e17: reject an oversize length on an I2C block read","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80931","datePublished":"2026-09-11T19:42:06.272Z","dateReserved":"2026-08-26T14:34:25.802Z","dateUpdated":"2026-09-13T06:28:11.350Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:18:56","lastModifiedDate":"2026-09-13 07:17:00","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"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","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"80931","Ordinal":"1","Title":"w1: ds28e17: reject an oversize length on an I2C block read","CVE":"CVE-2026-80931","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80931","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nw1: ds28e17: reject an oversize length on an I2C block read\n\nw1_f19_i2c_master_transfer() is the master_xfer for the DS28E17 1-Wire\nto I2C bridge. On an I2C_M_RECV_LEN read, it takes the length from the\ndevice. The downstream slave puts a length byte in buf[0]. The driver\nthen reads that many bytes into buf[1] with w1_f19_i2c_read().\n\nbuf[0] is controlled by the device and can be 0 to 255.\nw1_f19_i2c_read() only rejects a zero count. The caller buffer is\nI2C_SMBUS_BLOCK_MAX + 2, so 34 bytes. A length above 32 makes the read\nrun past it, up to about 222 bytes out of bounds.\n\nThe SMBus core does check buf[0] against I2C_SMBUS_BLOCK_MAX. That\ncheck runs after master_xfer returns. By then the write is already\ndone. i2c-algo-bit rejects an oversize length before it copies, and\nreturns -EPROTO.\n\nReject a length above I2C_SMBUS_BLOCK_MAX at both RECV_LEN sites, the\nsame way i2c-algo-bit does.","Type":"Description","Title":"w1: ds28e17: reject an oversize length on an I2C block read"}]}}}