CVE-2026-45865: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: mctp i2c: initialise event handler read bytes Set a 0xff value for i2c reads of an mctp-i2c device. Otherwise reads will return "val" from the i2c bus driver. For i2c-aspeed and i2c-npcm7xx that is a stack uninitialised u8. Tested with "i2ctransfer -y 1 r10@0x34" where 0x34 is a mctp-i2c instance, now it returns all 0xff.

Affected products

• Linux Linux Kernel: from 5.18, before 6.1.165 (fixed in 6.1.165); from 6.2, before 6.6.128 (fixed in 6.6.128); from 6.7, before 6.12.75 (fixed in 6.12.75); from 6.13, before 6.18.14 (fixed in 6.18.14); from 6.19, before 6.19.4 (fixed in 6.19.4)

Published 2026-05-27. Last modified 2026-06-25.