GHSA-V2FC-QM4H-8HQV

Nokogiri's Nokogiri::XSLT::Stylesheet#transform leaks a small heap allocation when passed a Ruby string parameter containing a null byte.

For applications that pass attacker-controlled input through XSLT.transform parameters, this may be a vector for a denial of service attack against long-running processes.

Mitigation

Upgrade to Nokogiri >= 1.19.3.

Users may also be able to mitigate this issue without upgrading by validating untrusted transform parameters before passing them to Nokogiri::XSLT::Stylesheet#transform.

Severity

The Nokogiri maintainers have evaluated this as Moderate Severity, CVSS 5.3.

Each leaked allocation is approximately 24–32 bytes, so meaningful memory growth requires sustained attacker-controlled traffic at high call rates. The bug does not cause memory corruption, information disclosure, or any change in the behavior of the transform itself, and the string-handling exception is raised as expected.

Applications that do not pass raw attacker-controlled bytes to XSLT parameters are unlikely to be affected in practice.

Resources

• CWE-401: Missing Release of Memory after Effective Lifetime

Credit

This vulnerability was responsibly reported by @Captainjack-kor.

GHSA-V2FC-QM4H-8HQV has a CVSS score of 5.3 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.19.3); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is GHSA-V2FC-QM4H-8HQV? GHSA-V2FC-QM4H-8HQV is a medium-severity security vulnerability in nokogiri (rubygems), affecting versions < 1.19.3. It is fixed in 1.19.3.
2. How severe is GHSA-V2FC-QM4H-8HQV? GHSA-V2FC-QM4H-8HQV has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of nokogiri are affected by GHSA-V2FC-QM4H-8HQV? nokogiri (rubygems) versions < 1.19.3 is affected.
4. Is there a fix for GHSA-V2FC-QM4H-8HQV? Yes. GHSA-V2FC-QM4H-8HQV is fixed in 1.19.3. Upgrade to this version or later.
5. Is GHSA-V2FC-QM4H-8HQV exploitable, and should I be worried? Whether GHSA-V2FC-QM4H-8HQV is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether GHSA-V2FC-QM4H-8HQV is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix GHSA-V2FC-QM4H-8HQV? Upgrade nokogiri to 1.19.3 or later.

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