How severe is GHSA-5v8h-3h3q-446p?

No CVSS score has been assigned to GHSA-5v8h-3h3q-446p yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-5v8h-3h3q-446p?

GHSA-5v8h-3h3q-446p affects the following packages: nokogiri (RubyGems). Ecosystems affected: RubyGems.

How do I fix GHSA-5v8h-3h3q-446p?

Update nokogiri to 1.19.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5v8h-3h3q-446p is resolved across your whole dependency graph.

How do I detect GHSA-5v8h-3h3q-446p 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 GHSA-5v8h-3h3q-446p 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 GHSA-5v8h-3h3q-446p actively exploited in the wild?

No public exploit code has been indexed for GHSA-5v8h-3h3q-446p 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.

What is the EPSS score for GHSA-5v8h-3h3q-446p?

GHSA-5v8h-3h3q-446p has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 36th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-5v8h-3h3q-446p?

GHSA-5v8h-3h3q-446p is classified as Use After Free (CWE-416). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-5v8h-3h3q-446p published, and has it been updated?

GHSA-5v8h-3h3q-446p was published on June 19, 2026 and was last updated on September 10, 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

Nokogiri: Possible Use-After-Free when `Nokogiri::XML::Document#encoding=` raises an exceptionGHSA-5v8h-3h3q-446p

GHSA-5v8h-3h3q-446p is a Use After Free vulnerability in nokogiri. A fix is available for nokogiri — see the affected versions and patch details below.

Also known asCVE-2026-57236

Published

Jun 19, 2026

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-5v8h-3h3q-446p.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs36th percentile — riskier than 36% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from 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

Calling Document#encoding= with an invalid encoding (e.g., a non-string, or a string containing a null byte) raises an exception, but only after freeing the document's current encoding string without replacing it. The document is left referencing freed memory, so the next call to Document#encoding reads invalid memory, which can cause a segfault or leak freed bytes into a Ruby String.

Affects the CRuby (libxml2) implementation only; JRuby is not affected.

Severity

The Nokogiri maintainers have evaluated this as low severity. Reaching it requires an unusual API-usage pattern that does not arise during normal use. The application must pass an invalid encoding to Document#encoding=, rescue the resulting exception, and then continue using the same document. Nokogiri 1.19.4 makes this pattern safe with no change to the public API. The document no longer references freed memory after the exception is raised.

Mitigation

Upgrade to Nokogiri 1.19.4 or later.

If users are unable to upgrade, avoid passing attacker-controlled values to Document#encoding=. Applications that only assign developer-authored encodings are not directly exposed.

Credit

This issue was responsibly reported by Zheng Yu from depthfirst.com.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`nokogiri`	all versions	1.19.4`bundle update nokogiri --conservative`

Affected Products

1 product · 1 configurations

Application

nokogirinokogiri

< 1.19.4

range

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 1.19.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5v8h-3h3q-446p 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 HatModerate

This flaw has an Important impact as Nokogiri's CRuby implementation in Red Hat products is vulnerable to a use-after-free when processing invalid encoding values. A remote unauthenticated attacker can trigger a segmentation fault causing denial of service, or leak freed memory contents into a Ruby String causing…

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 GHSA-5v8h-3h3q-446p (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat Satellite 6.16 for RHEL 8	`rubygem-nokogiri-0:1.15.7-3.el8sat`	RHSA-2026:50223
Red Hat Satellite 6.17 for RHEL 9	`rubygem-nokogiri-0:1.15.7-3.el9sat`	RHSA-2026:50222
Red Hat Satellite 6.18 for RHEL 9	`rubygem-nokogiri-0:1.15.7-3.el9sat`	RHSA-2026:50263
Red Hat Satellite 6.19 for RHEL 9	`rubygem-nokogiri-0:1.17.2-3.el9sat`	RHSA-2026:50221

Frequently Asked Questions

### Summary Calling `Document#encoding=` with an invalid encoding (e.g., a non-string, or a string containing a null byte) raises an exception, but only after freeing the document's current encoding string without replacing it. The document is left referencing freed memory, so the next call to `Document#encoding` reads invalid memory, which can cause a segfault or leak freed bytes into a Ruby `String`. Affects the CRuby (libxml2) implementation only; JRuby is not affected. ### Severity The Nokogiri maintainers have evaluated this as low severity. Reaching it requires an unusual API-usage p

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