How severe is CVE-2025-71407?

No CVSS score has been assigned to CVE-2025-71407 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-71407?

CVE-2025-71407 affects the following packages: nokogiri (RubyGems). Ecosystems affected: RubyGems.

How do I fix CVE-2025-71407?

Update nokogiri to 1.18.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-71407 is resolved across your whole dependency graph.

How do I detect CVE-2025-71407 in my RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nokogiri, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2025-71407 if there is no patch (or I can't update yet)?

Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

Is CVE-2025-71407 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-71407 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2025-71407 published, and has it been updated?

CVE-2025-71407 was published on August 25, 2026 and was last updated on August 30, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💎 RubyGems

Not in CISA KEV

CVE-2025-71407 — nokogiri

CVE-2025-71407 is a remote code execution vulnerability in nokogiri. A fix is available for nokogiri — see the affected versions and patch details below.

Nokogiri before 1.18.3 Stack Buffer Overflow and Use-After-Free

Also known asGHSA-vvfq-8hwr-qm4m

Published

Aug 25, 2026

Updated

Aug 30, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Aug 30, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

💎nokogiri

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Nokogiri v1.18.3 upgrades its dependency libxml2 to v2.13.6.

libxml2 v2.13.6 addresses:

CVE-2025-24928
- described at https://gitlab.gnome.org/GNOME/libxml2/-/issues/847
CVE-2024-56171
- described at https://gitlab.gnome.org/GNOME/libxml2/-/issues/828

Impact

CVE-2025-24928

Stack-buffer overflow is possible when reporting DTD validation errors if the input contains a long (~3kb) QName prefix.

CVE-2024-56171

Use-after-free is possible during validation against untrusted XML Schemas (.xsd) and, potentially, validation of untrusted documents against trusted Schemas if they make use of xsd:keyref in combination with recursively defined types that have additional identity constraints.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`nokogiri`	all versions	1.18.3`bundle update nokogiri --conservative`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nokogiri, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update nokogiri to 1.18.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-71407 is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

This CVE does not represent a flaw in Nokogiri, but is rather a duplicate assignment for different CVEs affecting libxml2 or libxslt. The rubygem-nokogiri packages as shipped in Red Hat products do not bundled libxml2 and libxslt, but rather use system packages of those libraries. This CVE is therefore not applicable…

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Source: Red Hat security advisory for CVE-2025-71407 (CC BY 4.0)

Frequently Asked Questions

## Summary Nokogiri v1.18.3 upgrades its dependency libxml2 to [v2.13.6](https://gitlab.gnome.org/GNOME/libxml2/-/releases/v2.13.6). libxml2 v2.13.6 addresses: - CVE-2025-24928 - described at https://gitlab.gnome.org/GNOME/libxml2/-/issues/847 - CVE-2024-56171 - described at https://gitlab.gnome.org/GNOME/libxml2/-/issues/828 ## Impact ### CVE-2025-24928 Stack-buffer overflow is possible when reporting DTD validation errors if the input contains a long (~3kb) QName prefix. ### CVE-2024-56171 Use-after-free is possible during validation against untrusted XML Schemas (.xsd) and, pot

O3 Security · Impact-Aware SCA

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