Summary
Withdrawn Advisory: Microsoft Knack ReDoS Vulnerability in the Introspection Module
Withdrawn Advisory
This advisory has been withdrawn because the attack surface of this vulnerability is outside of Knack's intended functionality. The maintainer states the following:
These CVEs are invalid. Knack is a CLI framework used by Azure CLI. It's a local library, not a web service. In addition, the regex is used to extract function and parameter docstrings from the source code. It is not used to match user input. Therefore, it does not expose any attack surface. There is no way to use it for ReDoS attack.
This link is maintained to preserve external references.
Original Description
Microsoft Knack 0.12.0 allows Regular expression Denial of Service (ReDoS) in the knack.introspection module (issue 2 of 2).
Impact
A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use. Typical impact: denial of service when input is crafted to trigger backtracking.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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In the interim: Rewrite the regular expression to avoid ambiguous repetition, or use a linear-time regex engine.
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2025-54364? CVE-2025-54364 is a low-severity inefficient regular expression (ReDoS) vulnerability in knack (pip), affecting versions <= 0.12.0. No fixed version is listed yet. A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use.
- Which versions of knack are affected by CVE-2025-54364? knack (pip) versions <= 0.12.0 is affected.
- Is there a fix for CVE-2025-54364? No fixed version is listed for CVE-2025-54364 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2025-54364 exploitable, and should I be worried? Whether CVE-2025-54364 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-54364 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-54364? No fixed version is listed yet. In the interim: Rewrite the regular expression to avoid ambiguous repetition, or use a linear-time regex engine.