Vulnerability · Published Aug 20, 2025 · Assigned by mitre
CVE-2025-54363
Medium 6.9
In plain English
A medium-severity regular-expression denial of service in Knack from Microsoft. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities).
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | knack | no fix listed | DEBIAN-CVE-2025-54363 |
| Debian:13 | knack | no fix listed | DEBIAN-CVE-2025-54363 |
| Debian:14 | knack | no fix listed | DEBIAN-CVE-2025-54363 |
| PyPI | knack | no fix listed | GHSA-6fxp-p9mg-q64w |
| Ubuntu:22.04:LTS | knack | no fix listed | UBUNTU-CVE-2025-54363 |
| Ubuntu:24.04:LTS | knack | no fix listed | UBUNTU-CVE-2025-54363 |
| Ubuntu:25.10 | knack | no fix listed | UBUNTU-CVE-2025-54363 |
| Ubuntu:26.04:LTS | knack | no fix listed | UBUNTU-CVE-2025-54363 |
| Ubuntu:26.10 | knack | no fix listed | UBUNTU-CVE-2025-54363 |
Affected products (as reported)
Weakness: CWE-1333 · Vector: 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