Medium 5.5Published May 27, 2026

CVE-2026-45865mctp i2c: initialise event handler read bytes

Updated under an hour ago (Oct 27, 2026, 1:50 AM ET)

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Exploited in the last 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.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: May 27, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from f5b8abf9fc3dacd7529d363e26fe8230935d65f8 before 93e01e837e105299f1c259ef71f6e1ec4fe806e3; from f5b8abf9fc3dacd7529d363e26fe8230935d65f8 before 11f83253244060b5de5eac787f61ae3f3e559d01; from f5b8abf9fc3dacd7529d363e26fe8230935d65f8 before fa9861e5c8af7651dddfa8d490aaada17ae33b6c; from f5b8abf9fc3dacd7529d363e26fe8230935d65f8 before 6ff2ebfef75fbc57d937d8fbe738b967edf2d331; from f5b8abf9fc3dacd7529d363e26fe8230935d65f8 before 1eeedb310229bfee9dd4d992e5bba33fe1378a8f; from f5b8abf9fc3dacd7529d363e26fe8230935d65f8 before 2a14e91b6d76639dac70ea170f4384c1ee3cb48d	CNA record
linux linux_kernel linux:linux_kernel	from 5.18 before 6.1.165; from 6.2 before 6.6.128; from 6.7 before 6.12.75; from 6.13 before 6.18.14; from 6.19 before 6.19.4	NVD

References

References

https://git.kernel.org/stable/c/93e01e837e105299f1c259ef71f6e1ec4fe806e3	patch
https://git.kernel.org/stable/c/11f83253244060b5de5eac787f61ae3f3e559d01	patch
https://git.kernel.org/stable/c/fa9861e5c8af7651dddfa8d490aaada17ae33b6c	patch
https://git.kernel.org/stable/c/6ff2ebfef75fbc57d937d8fbe738b967edf2d331	patch
https://git.kernel.org/stable/c/1eeedb310229bfee9dd4d992e5bba33fe1378a8f	patch
https://git.kernel.org/stable/c/2a14e91b6d76639dac70ea170f4384c1ee3cb48d	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.