mechanize vulnerable to ReDoS
Priority HIGH 72CWE-1333Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-1333.
Summary
mechanize, a library for automatically interacting with HTTP web servers, contains a regular expression that is vulnerable to regular expression denial of service (ReDoS) prior to version 0.4.6. If a web server responds in a malicious way, then mechanize could crash. Version 0.4.6 has a patch for the issue.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.28661 98th percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix Fixed mechanize (python-mechanize): 0.4.6mechanize (PyPI): 0.4.6
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| python-mechanize | mechanize | 0.4.6 to before 0.4.6 | 0.4.6 | Patch available | CNA |
| — | mechanize (PyPI) | before 0.4.6 | 0.4.6 | Patch available | GHSA-g3pv-pj5f-3hfq |
- mechanize Vendorpython-mechanize Affected 0.4.6 to before 0.4.6 Fixed in 0.4.6 Patch available CNA
- mechanize (PyPI) Vendor— Affected before 0.4.6 Fixed in 0.4.6 Patch available GHSA-g3pv-pj5f-3hfq
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mechanize_project:mechanize:*:*:*:*:*:python:*:* | before 0.4.6 | Vulnerable | Mechanize Project |
- cpe:2.3:a:mechanize_project:mechanize:*:*:*:*:*:python:*:* Versions before 0.4.6 Vulnerable ·Mechanize Project
Remediation
- Fix · CNA mechanize (python-mechanize) Fixed in 0.4.6
- Fix · GHSA-g3pv-pj5f-3hfq mechanize (PyPI) Fixed in 0.4.6 Advisory →
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-32837
- 2026-10-03 Alias added: GHSA-g3pv-pj5f-3hfq
References
Exploit 2
Patch 1
Advisory 3
More Mechanize Project Mechanize vulnerabilities
- TI-2021-04389 Command Injection Vulnerability in Mechanize CVSS 3.1HIGH 8.3
- TI-2022-13078 Authorization header leak in rubygem Mechanize CVSS 3.1HIGH 7.5
Sources
- CVE-2021-32837 · CVE Program
- CVE-2021-32837 · NVD
- FIRST EPSS
- GHSA-g3pv-pj5f-3hfq · GitHub Advisory Database · CC BY 4.0
- CVE-2021-32837 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences