CVE-2021-32837

Name: CVE-2021-32837
Creator: NVD / NIST
Published: 2023-01-17T22:15:10.533+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 26.71%

Last modified Jun 17, 2026

CVE-2021-32837 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 26.71% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

26.71%

97.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-1333

Affected Software

Vendor	Product	Versions
Mechanize Project	Mechanize	< 0.4.6

References

https://github.com/python-mechanize/mechanize/blob/3acb1836f3fd8edc5a758a417dd46b53832ae3b5/mechanize/_urllib2_fork.py#L878-L879Exploit, Third Party Advisory
https://github.com/python-mechanize/mechanize/commit/dd05334448e9f39814bab044d2eaa5ef69b410d6Patch, Third Party Advisory
https://github.com/python-mechanize/mechanize/releases/tag/v0.4.6Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/06/msg00022.html
https://securitylab.github.com/advisories/GHSL-2021-108-python-mechanize-mechanize/Exploit, Third Party Advisory
https://github.com/python-mechanize/mechanize/blob/3acb1836f3fd8edc5a758a417dd46b53832ae3b5/mechanize/_urllib2_fork.py#L878-L879Exploit, Third Party Advisory
https://github.com/python-mechanize/mechanize/commit/dd05334448e9f39814bab044d2eaa5ef69b410d6Patch, Third Party Advisory
https://github.com/python-mechanize/mechanize/releases/tag/v0.4.6Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/06/msg00022.html
https://lists.debian.org/debian-lts-announce/2025/12/msg00028.html
https://securitylab.github.com/advisories/GHSL-2021-108-python-mechanize-mechanize/Exploit, Third Party Advisory

Timeline

Published: Jan 17, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-32837?

How severe is CVE-2021-32837?

CVE-2021-32837 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 26.71% probability of exploitation in the next 30 days.

How do I fix CVE-2021-32837?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-32837?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST