{"id":"CVE-2026-80931","title":"w1: ds28e17: reject an oversize length on an I2C block read","summary":"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 …","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-125"],"vendor":"Linux","product":"Linux","affected":["Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < b30c021c6073559ea6851b522d8a17a524a27b4a","Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < 1d08877fc37e90945df38d255715bd1d6c052d46","Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < bf76d61e118b7044600a65775a3bf8adc2c6823d","Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < 0f6496b34cc2919420f303b2aabdd9f71e084b56","Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < cb55c5da9828f77db2a2701316949d4de1e9b773","Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < ae0c79a8527044e54d81fd5a3b49ce6177633758","Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < 6df05f630c84a109736642362e452089886f9974","Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < 169ae5e65e5aaf213b6a578f6478a9fd2e523606","Linux 4.15"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:45:15.065Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80931","references":[{"url":"https://git.kernel.org/stable/c/b30c021c6073559ea6851b522d8a17a524a27b4a"},{"url":"https://git.kernel.org/stable/c/1d08877fc37e90945df38d255715bd1d6c052d46"},{"url":"https://git.kernel.org/stable/c/bf76d61e118b7044600a65775a3bf8adc2c6823d"},{"url":"https://git.kernel.org/stable/c/0f6496b34cc2919420f303b2aabdd9f71e084b56"},{"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"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80931.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-80931"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532277"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80931"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80931"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80931.mbox"}],"tags":["cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00129,"epssPercentile":0.02553,"scores":{"cna":7.8,"vendor":5.5},"ingestedAt":"2026-09-14T15:23:07.455Z","slug":"CVE-2026-80931","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < b30c021c6073559ea6851b522d8a17a524a27b4a`\n- `Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < 1d08877fc37e90945df38d255715bd1d6c052d46`\n- `Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < bf76d61e118b7044600a65775a3bf8adc2c6823d`\n- `Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < 0f6496b34cc2919420f303b2aabdd9f71e084b56`\n- `Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < cb55c5da9828f77db2a2701316949d4de1e9b773`\n- `Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < ae0c79a8527044e54d81fd5a3b49ce6177633758`\n- `Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < 6df05f630c84a109736642362e452089886f9974`\n- `Linux >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175 < 169ae5e65e5aaf213b6a578f6478a9fd2e523606`\n- `Linux 4.15`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80931.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":224826,"id":"CVE-2026-80931","ts":1792401565875,"field":"cvss","old":"5.5","new":"7.8"},{"seq":224825,"id":"CVE-2026-80931","ts":1792401565875,"field":"severity","old":"medium","new":"high"},{"seq":202771,"id":"CVE-2026-80931","ts":1789403715820,"field":"cvss","old":"7.8","new":"5.5"},{"seq":202770,"id":"CVE-2026-80931","ts":1789403715820,"field":"severity","old":"high","new":"medium"},{"seq":183634,"id":"CVE-2026-80931","ts":1789356676191,"field":"cvss","old":"7.8","new":"4.7"},{"seq":183633,"id":"CVE-2026-80931","ts":1789356676191,"field":"severity","old":"high","new":"medium"},{"seq":153112,"id":"CVE-2026-80931","ts":1789285349056,"field":"cvss","old":null,"new":"7.8"},{"seq":153111,"id":"CVE-2026-80931","ts":1789285349056,"field":"severity","old":"none","new":"high"},{"seq":147460,"id":"CVE-2026-80931","ts":1789270210994,"field":"cvss","old":null,"new":"4.7"},{"seq":147459,"id":"CVE-2026-80931","ts":1789270210994,"field":"severity","old":"none","new":"medium"},{"seq":109212,"id":"CVE-2026-80931","ts":1789183730747,"field":"cvss","old":null,"new":"4.7"},{"seq":109211,"id":"CVE-2026-80931","ts":1789183730747,"field":"severity","old":"none","new":"medium"}]}