VulnerabilityPublished 13 Jan 2026Updated 19 Oct 2026

CVE-2025-68816: Linux kernel · net/mlx5: fw_tracer, Validate format string parameters

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in b35966042d20b14e2d83330049f77deec5229749 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 12:42 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS

0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-06-16.

Patch

Available – fixed in b35966042d20b14e2d83330049f77deec5229749, 95624b731c490a4b849844269193a233d6d556a0, 768d559f466cdd72849110a7ecd76a21d52dcfe3 +4

Exploitation evidence

Disclosed: evidence found.
CVE published 13 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 70dd6fdb8987b14f7b6105f6be0617299e459398, < b35966042d20b14e2d83330049f77deec5229749	Fixed in b35966042d20b14e2d83330049f77deec5229749
LinuxLinux	Affected ≥ 70dd6fdb8987b14f7b6105f6be0617299e459398, < 95624b731c490a4b849844269193a233d6d556a0	Fixed in 95624b731c490a4b849844269193a233d6d556a0
LinuxLinux	Affected ≥ 70dd6fdb8987b14f7b6105f6be0617299e459398, < 768d559f466cdd72849110a7ecd76a21d52dcfe3	Fixed in 768d559f466cdd72849110a7ecd76a21d52dcfe3
LinuxLinux	Affected ≥ 70dd6fdb8987b14f7b6105f6be0617299e459398, < 45bd283b1d69e2c97cddcb9956f0e0261fc4efd7	Fixed in 45bd283b1d69e2c97cddcb9956f0e0261fc4efd7
LinuxLinux	Affected ≥ 70dd6fdb8987b14f7b6105f6be0617299e459398, < 38ac688b52ef26a88f8bc4fe26d24fdd0ff91e5d	Fixed in 38ac688b52ef26a88f8bc4fe26d24fdd0ff91e5d
LinuxLinux	Affected ≥ 70dd6fdb8987b14f7b6105f6be0617299e459398, < 8c35c2448086870509ede43947845be0833251f0	Fixed in 8c35c2448086870509ede43947845be0833251f0

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.

CWE-134Use of Externally-Controlled Format String (opens in a new tab)
Base weaknessLikelihood of exploit: High
The product uses a function that accepts a format string as an argument, but the format string originates from an external source.
Requirements
Choose a language that is not subject to this flaw.
Implementation
Ensure that all format string functions are passed a static string which cannot be controlled by the user, and that the proper number of arguments are always sent to that function as well. If at all possible, use functions that do not support the %n operator in format strings.
Build and Compilation
Run compilers and linkers with high warning levels, since they may detect incorrect usage.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V5.4.2 (opens in a new tab)
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
Attack patterns
Format String Injection (opens in a new tab)
String Format Overflow in syslog() (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

WeaknessesCWE-134

Technical details

References

Community reviews

Related threats