CVE-2026-45865: 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 ...

Description

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.

Metrics

CVSS 3.1

5.5/10

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

EPSS Probability

0.16%

5.1th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	>= 5.18, < 6.1.165
Linux	Linux Kernel	>= 6.2, < 6.6.128
Linux	Linux Kernel	>= 6.7, < 6.12.75
Linux	Linux Kernel	>= 6.13, < 6.18.14
Linux	Linux Kernel	>= 6.19, < 6.19.4

References

Timeline

Published: May 27, 2026
Last Modified: Jun 25, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-45865?

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.

How severe is CVE-2026-45865?

CVE-2026-45865 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.16% probability of exploitation in the next 30 days.

How do I fix CVE-2026-45865?

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.