# CVE-2016-3630: Mercurial arbitrary code execution vulnerability

Source: https://junglewise.ai/threats/cve-2016-3630-mercurial-arbitrary-code-execution-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2016-04-13  
License: CC BY 4.0 with a link back

CVE-2016-3630 · Severity: low · CVSS 3 · Published 2016-04-13

The binary delta decoder in Mercurial before 3.7.3 allows remote attackers to execute arbitrary code via a (1) clone, (2) push, or (3) pull command, related to (a) a list sizing rounding error and (b) short records.

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

## Quick answers

**Is CVE-2016-3630 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2016-3630 being exploited in the wild.

**How severe is CVE-2016-3630?** Low severity, with a CVSS score of 3, published 13 April 2016.

**Which products and versions are affected?** mercurial (PyPI) ECOSYSTEM:introduced=0,fixed=3.7.3.

**Is there a fix for CVE-2016-3630?** Yes. mercurial (PyPI): upgrade to 3.7.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2016-3630?** 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 3.7.3 or later

  ```sh
  pip install "mercurial>=3.7.3"
  ```


## Affected products

- mercurial (PyPI) ECOSYSTEM:introduced=0,fixed=3.7.3

## Identifiers

- CVE-2016-3630
- GHSA-9vjf-jjcq-3gh7
- PYSEC-2016-29

## Related threats

- [PYSEC-2026-666 - Mercurial Directory traversal vulnerability](https://junglewise.ai/threats/cve-2008-2942-mercurial-directory-traversal-vulnerability)
- [PYSEC-2026-665 - Mercurial Improper Certificate Validation vulnerability](https://junglewise.ai/threats/cve-2010-4237-mercurial-improper-certificate-validation-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)