CVE-2025-68816 net/mlx5: fw_tracer, Validate format string parameters
Malicious firmware can send unsafe format strings to the mlx5 tracer, causing kernel crashes or potential code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-68816?
CVE-2025-68816 is a memory corruption vulnerability in Linux, published on 13 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: fw_tracer, Validate format string parameters
Add validation for format string parameters in the firmware tracer to prevent potential security vulnerabilities and crashes from malformed format strings received from firmware.
The firmware tracer receives format strings from the device firmware and uses them to format trace messages. Without proper validation, bad firmware could provide format strings with invalid format specifiers (e.g., %s, %p, %n) that could lead to crashes, or other undefined behavior.
Add mlx5_tracer_validate_params() to validate that all format specifiers in trace strings are limited to safe integer/hex formats (%x, %d, %i, %u, %llx, %lx, etc.). Reject strings containing other format types that could be used to access arbitrary memory or cause crashes. Invalid format strings are added to the trace output for visibility with "BAD_FORMAT: " prefix.
Weakness: CWE-134
Which versions are affected by CVE-2025-68816?
How do I fix CVE-2025-68816?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-68816 being exploited?
There is no known exploitation of CVE-2025-68816 in the wild and no public exploit code.
Sources
Also known as AZL-74430, BELL-CVE-2025-68816, DEBIAN-CVE-2025-68816, GHSA-446v-vm34-72r6, ROOT-OS-DEBIAN-11-CVE-2025-68816, ROOT-OS-DEBIAN-12-CVE-2025-68816 and 4 more.