# CVE-2010-4237: PYSEC-2026-665 - Mercurial Improper Certificate Validation vulnerability

Source: https://junglewise.ai/threats/cve-2010-4237-mercurial-improper-certificate-validation-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-02  
License: CC BY 4.0 with a link back

CVE-2010-4237 · Severity: low · CVSS 3.1 · Published 2026-07-02

Mercurial Improper Certificate Validation vulnerability

Technologies: [mercurial (PyPI)](https://junglewise.ai/threats/technologies/mercurial). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2010-4237 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2010-4237 being exploited in the wild.

**How severe is CVE-2010-4237?** Low severity, with a CVSS score of 3.1, published 2 July 2026.

**Which products and versions are affected?** mercurial (PyPI) ECOSYSTEM:introduced=0,fixed=1.6.4.

**Is there a fix for CVE-2010-4237?** Yes. mercurial (PyPI): upgrade to 1.6.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2010-4237?** Check whether you run mercurial (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- mercurial (PyPI): upgrade to 1.6.4 or later

  ```sh
  pip install "mercurial>=1.6.4"
  ```


## Affected products

- mercurial (PyPI) ECOSYSTEM:introduced=0,fixed=1.6.4

## Identifiers

- CVE-2010-4237
- GHSA-7gf7-7wx4-mxmw
- PYSEC-2026-665

## Related threats

- [PYSEC-2026-666 - Mercurial Directory traversal vulnerability](https://junglewise.ai/threats/cve-2008-2942-mercurial-directory-traversal-vulnerability)
- [JGit Improper Input Validation vulnerability](https://junglewise.ai/threats/cve-2014-9390-jgit-improper-input-validation-vulnerability)
- [Mercurial Path Traversal/Link Following vulnerability](https://junglewise.ai/threats/cve-2019-3902-mercurial-path-traversal-link-following-vulnerability)
- [PYSEC-2018-91 - cext/manifest.c in Mercurial before 4.7.2 has an out-of-bounds read during parsing of a malformed manifest entry.](https://junglewise.ai/threats/cve-2018-17983-mercurial-out-of-bounds-read-vulnerability)
- [Mercurial Improper Input Validation vulnerability](https://junglewise.ai/threats/cve-2018-13346-mercurial-improper-input-validation-vulnerability)