CVE-2026-90416

What the bug is

get_param() reads a congestion parameter as a u32 but formats it with the signed "%d" into an 11-byte stack buffer. A value with bit 31 set, such as 0x80000000, renders as "-2147483648\n" whose full length is 12. snprintf() stores only 11 bytes yet returns 12, so simple_read_from_buffer() treats 12 bytes as valid and reads one byte past lbuf[]. Size the buffer for the widest unsigned decimal, format with "%u" to match the u32, and use scnprintf() so the length passed to simple_read_from_buffer() reflects the bytes actually stored.

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/infiniband/hw/mlx5/cong.c

What this is

MELLANOX MLX5 IB driverMAINTAINERS section matched on drivers/infiniband/hw/mlx5/ · linux-rdma@vger.kernel.org · Supported

Kernel module

mlx5_ib

Check it on the machine

grep -wE 'CONFIG_INFINIBAND|CONFIG_MLX5_INFINIBAND' /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.

lsmod | grep -w mlx5_ib

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookwormm
• trixieMnot built on armel/rpi
• forky, sid, bookworm · linux-6.12m

m

a loadable module on every flavour - check lsmod, can be blacklisted

M

a module where it is built at all; some flavours do not build it

Build switches

CONFIG_INFINIBAND, CONFIG_MLX5_INFINIBAND

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

2026-09-17 (31 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.21%, higher than 10.5% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/infiniband

Upstream fixes

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

Introduced	Fixed in	Commit
4.14	5.10.270	1c5b4f76cd73
4.14	5.15.221	06b62758f81e
4.14	6.1.188	d809cf3f0ed9
4.14	6.6.157	0b0122fcc923
4.14	6.12.110	ce8dfd32a33b
4.14	6.18.52	4599311e78e8
4.14	7.2.6	c75ee076fa09
4.14	7.3	03826bc1fa6c

Debian advisories