CVE-2026-64087

What the bug is

adm1266_nvmem_read_blackbox() loops over a record_count that comes straight from byte 3 of the BLACKBOX_INFO response. The destination buffer is data->dev_mem, sized for the nvmem cell's declared 2048 bytes (ADM1266_BLACKBOX_MAX_RECORDS * ADM1266_BLACKBOX_SIZE = 32 * 64). A device that reports a record_count greater than 32 -- whether due to firmware bugs, bus corruption, or a non-responsive slave returning 0xff -- would walk read_buff past the end of the dev_mem allocation on the trailing iterations. Cap record_count at ADM1266_BLACKBOX_MAX_RECORDS (introduced here) before entering the loop and return -EIO on any larger value, so a malformed BLACKBOX_INFO response cannot drive the loop out of bounds.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/hwmon/pmbus/adm1266.c

What this is

HARDWARE MONITORINGMAINTAINERS section matched on drivers/hwmon/ · linux-hwmon@vger.kernel.org · Maintained

Kernel module

none to look for. The file would have gone into adm1266, and Debian does not compile it into that module, so finding adm1266 in lsmod would say nothing about this CVE.

Check it on the machine

grep -wE 'CONFIG_HWMON|CONFIG_PMBUS|CONFIG_SENSORS_ADM1266' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

Show whether Debian builds this, per release

Debian does not build this code. In 4 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.

• bookworm, trixie, forky, sidn

n

not enabled on any flavour - this release does not build the code

Build switches

CONFIG_HWMON, CONFIG_PMBUS, CONFIG_SENSORS_ADM1266

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-07-19 (3 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.13%, higher than 2.2% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/hwmon

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
5.10	5.10.258	adcb163ad7ca
5.10	5.15.209	c2c56092710f
5.10	6.1.175	5469e1e7c411
5.10	6.6.142	f85c81e93dbd
5.10	6.12.92	0e791cd0140f
5.10	6.18.34	75c862adf3d3
5.10	7.0.11	231db52a5b64
5.10	7.1	4afca954622d