CVE-2025-54363: Withdrawn Advisory Denial of Service Vulnerability

LOW
Advisory Identifier: GHSA-6fxp-p9mg-q64w
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CWE-1333
Published
Advisory Summary

CVE-2025-54363 is a LOW denial of service vulnerability (CWE-1333: Inefficient Regular Expression Complexity) affecting Withdrawn Advisory libraries in the PyPI ecosystem. The issue involves microsoft knack redos vulnerability in the introspection module. Remediation is available in the latest vendor maintenance releases.

CVE-2025-54363 at a Glance

CVE Identifier CVE-2025-54363
GHSA Identifier GHSA-6fxp-p9mg-q64w
Severity LOW
CVSS v3.1 Base Score N/A
CWE Classification CWE-1333: Inefficient Regular Expression Complexity
Affected Product Withdrawn Advisory
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2025-54363

To remediate this vulnerability, upgrade all affected Withdrawn Advisory dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

knack fixed: Latest secure release 
pip install knack>=Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show knack

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2025-54363, inspect your installed packages using pip:

pip show knack

Analyze the terminal output to locate any version of Withdrawn Advisory in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The pip show knack command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1333: Inefficient Regular Expression Complexity, where the product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential. In Withdrawn Advisory, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Withdrawn Advisory This advisory has been withdrawn because the attack surface of this vulnerability is outside of Knack's intended functionality.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](https://github.com/Azure/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 1 of 2).

CVE-2025-54363 Affected Withdrawn Advisory Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
knack
pypi/knack
PyPI
≤ 0.12.0

References

NVD — CVE-2025-54363 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-54363
Withdrawn Advisory Source Repository REPOSITORY
https://github.com/microsoft/knack/issues/281
Withdrawn Advisory Source Repository REPOSITORY
https://github.com/microsoft/knack/issues/281#issuecomment-3218922941
Withdrawn Advisory Source Repository REPOSITORY
https://github.com/microsoft/knack
www.vulncheck.com/advisories/microsof... WEB
https://www.vulncheck.com/advisories/microsoft-knack-python-package-regular-expression-dos

Frequently Asked Questions

What is CVE-2025-54363?
CVE-2025-54363 is a security vulnerability in Withdrawn Advisory involving Microsoft Knack ReDoS Vulnerability in the Introspection Module under CWE-1333: Inefficient Regular Expression Complexity.
Which Withdrawn Advisory versions are affected?
Affected versions include releases prior to current release patches across affected packages: knack.
What version fixes CVE-2025-54363?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is knack affected?
Yes, knack is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What CWE is associated with CVE-2025-54363?
CVE-2025-54363 is classified under CWE-1333: Inefficient Regular Expression Complexity (The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.).
How can I check PyPI dependencies for CVE-2025-54363?
Run the dependency tree command: 'pip show knack'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-6fxp-p9mg-q64w",
  "modified" : "2025-08-29T20:14:31Z",
  "published" : "2025-08-20T03:30:20Z",
  "withdrawn" : "2025-08-29T20:14:31Z",
  "aliases" : [ "CVE-2025-54363" ],
  "summary" : "Withdrawn Advisory: Microsoft Knack ReDoS Vulnerability in the Introspection Module",
  "details" : "### Withdrawn Advisory\nThis advisory has been withdrawn because the attack surface of this vulnerability is outside of Knack's intended functionality. The maintainer states the following:\n\n> These CVEs are invalid. Knack is a CLI framework used by [Azure CLI](https://github.com/Azure/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.\n\nThis link is maintained to preserve external references.\n\n### Original Description\nMicrosoft Knack 0.12.0 allows Regular expression Denial of Service (ReDoS) in the knack.introspection module (issue 1 of 2).",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "knack"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.12.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-54363"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/microsoft/knack/issues/281"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/microsoft/knack/issues/281#issuecomment-3218922941"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/microsoft/knack"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/microsoft-knack-python-package-regular-expression-dos"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1333" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-08-21T15:00:54Z",
    "nvd_published_at" : "2025-08-20T03:15:35Z"
  }
}