Skip to main content
CVE-2025-54364VulnerabilityPublished Updated

CVE-2025-54364: Microsoft Knack · ReDoS

Affects Microsoft KnackSource CVE Database V5

0

Not known to be exploited · CVSS 6.9 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score
6.9Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 29% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 20 Aug 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 2026-10-25.

What to do

Affected software

ProductAffectedFixed in
Microsoft KnackAffected
  • =0.12.0
Fixed in–

AI-suggested

To mitigate this vulnerability, European organizations should: 1) Immediately audit their environments to identify usage of Microsoft Knack version 0.12.0, especially within Azure CLI installations. 2) Monitor official Microsoft and Azure CLI channels for patches or updates addressing CVE-2025-54364 and apply them promptly once available. 3) Implement input validation and sanitization controls to prevent injection or manipulation of docstring content that could trigger the vulnerable regex pattern. 4) Restrict local access and enforce strict access controls to limit the ability of attackers to inject malicious docstrings, including hardening development and deployment environments. 5) Employ resource monitoring and alerting to detect unusual CPU usage patterns indicative of ReDoS attempts. 6) Consider isolating or sandboxing components that process docstrings to contain potential resource exhaustion impacts. 7) Educate developers and DevOps teams about the risks of inefficient regex patterns and encourage secure coding practices to avoid similar vulnerabilities in custom code.

Description

Microsoft Knack 0.12.0 allows Regular expression Denial of Service (ReDoS) in the knack.introspection module.option_descriptions employs an inefficient regular expression pattern: "\s(:param)\s+(.+?)\s:(.*)" that is susceptible to catastrophic backtracking when processing crafted docstrings containing a large volume of whitespace without a terminating colon. An attacker who can control or inject docstring content into affected applications can trigger excessive CPU consumption. This software is used by Azure CLI.

References

Community reviews

Loading reviews…