CVE-2025-54363: microsoft knack
Vulnerability summary
CVE-2025-54363 is a medium (CVSS 6.9) vulnerability in microsoft knack. EPSS estimates a 0.41% chance of exploitation in the next 30 days, higher than 34.4% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 0 · Related 2Timeline
- 20-08-2025PublishedVulnerability first disclosed.
- 21-08-2025Last modifiedVulnerability information updated.
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.
CVSS metrics
7 scores · 7 sources · 1 version- OSV · PypiEcosystem advisory · calculated5.1MediumCVSS: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:UDiffers
- OSV · UbuntuEcosystem advisory · calculated6.9MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- OSV · DebianEcosystem advisory · calculated6.9MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · WolfiEcosystem advisory · calculated6.9MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- OSV · ChainguardEcosystem advisory · calculated6.9MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- NVDNIST6.9MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS trend
Probability
0.41%
Chance of exploitation in the next 30 days
Percentile
34%
Versus all other CVEs
30-day change
+0.02 pp
From 0.40% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Chainguard7 products
- az< 2.79.0-r0
- py3-knack< 0.12.0-r3
- py3-supported-knack< 0.12.0-r3
- py3.10-knack< 0.12.0-r3
- py3.11-knack< 0.12.0-r3
Wolfi7 products
- az< 2.79.0-r0
- py3-knack< 0.12.0-r3
- py3-supported-knack< 0.12.0-r3
- py3.10-knack< 0.12.0-r3
- py3.11-knack< 0.12.0-r3
Debian1 product
- knackAll versions (No fix recorded)
Microsoft1 product
- knack0.12.0
PyPI1 product
- knack≤ 0.12.0
Ubuntu1 product
- knackAll versions (No fix recorded)
6 vendors · 18 products
