Linux Kernel up to 6.19-rc1 mlx5_tracer_validate_params format string

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.2/6.19-rc1. This affects the function mlx5_tracer_validate_params. The manipulation results in format string. This vulnerability is identified as CVE-2025-68816. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.2/6.19-rc1. It has been classified as critical. Affected is the function mlx5_tracer_validate_params. The manipulation with an unknown input leads to a format string vulnerability. CWE is classifying the issue as CWE-134. The product uses a function that accepts a format string as an argument, but the format string originates from an external source. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2025-68816 since 12/24/2025. The exploitability is told to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 02/12/2026).

The vulnerability scanner Nessus provides a plugin with the ID 298659 (Debian dla-4476 : linux-config-6.1 - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.160, 6.6.120, 6.12.64, 6.18.3 or 6.19-rc2 eliminates this vulnerability. Applying the patch 38ac688b52ef26a88f8bc4fe26d24fdd0ff91e5d/8ac688c0e430dab19f6a9b70df94b1f635612c1a/45bd283b1d69e2c97cddcb9956f0e0261fc4efd7/8c35c2448086870509ede43947845be0833251f0/b35966042d20b14e2d83330049f77deec5229749 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (298659). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.159
• 6.6.119
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.12.58
• 6.12.59
• 6.12.60
• 6.12.61
• 6.12.62
• 6.12.63
• 6.18.0
• 6.18.1
• 6.18.2
• 6.19-rc1

License

• open-source

Website

• Vendor: https://www.kernel.org/

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