CVE-2025-54363
CVE-2025-54363 is a medium-severity vulnerability with a CVSS 4.0 base score of 6.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1333.
Key facts
- Severity: Medium (CVSS 4.0 base score 6.9)
- EPSS exploit prediction: 0% (29th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2025-25266
- Weakness: CWE-1333
- Published:
- Last modified:
Description
Microsoft Knack 0.12.0 allows Regular expression Denial of Service (ReDoS) in the knack.introspection module. extract_full_summary_from_signature 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.
Frequently asked questions
- What is CVE-2025-54363?
- Microsoft Knack 0.12.0 allows Regular expression Denial of Service (ReDoS) in the knack.introspection module. extract_full_summary_from_signature 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.
- How severe is CVE-2025-54363?
- CVE-2025-54363 has a CVSS 4.0 base score of 6.9, rated medium severity.
- Is CVE-2025-54363 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2025-54363?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2025-54363 have an EU (EUVD) identifier?
- Yes. CVE-2025-54363 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-25266.
- When was CVE-2025-54363 published?
- CVE-2025-54363 was published on 2025-08-20 and last updated on 2026-06-17.
References
- https://github.com/microsoft/knack
- https://github.com/microsoft/knack/issues/281
- https://www.vulncheck.com/advisories/microsoft-knack-python-package-regular-expression-dos
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