CVE-2026-80931: Linux Vulnerability (CVSS 7.8)

Description

In the Linux kernel, the following vulnerability has been resolved: w1: ds28e17: reject an oversize length on an I2C block read w1_f19_i2c_master_transfer() is the master_xfer for the DS28E17 1-Wire to I2C bridge. On an I2C_M_RECV_LEN read, it takes the length from the device. The downstream slave puts a length byte in buf[0]. The driver then reads that many bytes into buf[1] with w1_f19_i2c_read(). buf[0] is controlled by the device and can be 0 to 255. w1_f19_i2c_read() only rejects a zero count. The caller buffer is I2C_SMBUS_BLOCK_MAX + 2, so 34 bytes. A length above 32 makes the read run past it, up to about 222 bytes out of bounds. The SMBus core does check buf[0] against I2C_SMBUS_BLOCK_MAX. That check runs after master_xfer returns. By then the write is already done. i2c-algo-bit rejects an oversize length before it copies, and returns -EPROTO. Reject a length above I2C_SMBUS_BLOCK_MAX at both RECV_LEN sites, the same way i2c-algo-bit does.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.13%

2.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= ebc4768ac4971eab4b570e733e47ac9dfd0e4175, < b30c021c6073559ea6851b522d8a17a524a27b4a; >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175, < 1d08877fc37e90945df38d255715bd1d6c052d46; >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175, < bf76d61e118b7044600a65775a3bf8adc2c6823d; >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175, < 0f6496b34cc2919420f303b2aabdd9f71e084b56; >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175, < cb55c5da9828f77db2a2701316949d4de1e9b773; >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175, < ae0c79a8527044e54d81fd5a3b49ce6177633758; >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175, < 6df05f630c84a109736642362e452089886f9974; >= ebc4768ac4971eab4b570e733e47ac9dfd0e4175, < 169ae5e65e5aaf213b6a578f6478a9fd2e523606
Linux	Linux	4.15

References

Timeline

Published: Sep 11, 2026
Last Modified: Sep 14, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-80931?

In the Linux kernel, the following vulnerability has been resolved: w1: ds28e17: reject an oversize length on an I2C block read w1_f19_i2c_master_transfer() is the master_xfer for the DS28E17 1-Wire to I2C bridge. On an I2C_M_RECV_LEN read, it takes the length from the device. The downstream slave puts a length byte in buf[0]. The driver then reads that many bytes into buf[1] with w1_f19_i2c_read(). buf[0] is controlled by the device and can be 0 to 255. w1_f19_i2c_read() only rejects a zero count. The caller buffer is I2C_SMBUS_BLOCK_MAX + 2, so 34 bytes. A length above 32 makes the read run past it, up to about 222 bytes out of bounds. The SMBus core does check buf[0] against I2C_SMBUS_BLOCK_MAX. That check runs after master_xfer returns. By then the write is already done. i2c-algo-bit rejects an oversize length before it copies, and returns -EPROTO. Reject a length above I2C_SMBUS_BLOCK_MAX at both RECV_LEN sites, the same way i2c-algo-bit does.

How severe is CVE-2026-80931?

CVE-2026-80931 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.13% probability of exploitation in the next 30 days.

How do I fix CVE-2026-80931?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

View all 2026CVEs →