How severe is GHSA-353f-x4gh-cqq8?

No CVSS score has been assigned to GHSA-353f-x4gh-cqq8 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-353f-x4gh-cqq8?

GHSA-353f-x4gh-cqq8 affects the following packages: nokogiri (RubyGems). Ecosystems affected: RubyGems.

How do I fix GHSA-353f-x4gh-cqq8?

Update nokogiri to 1.18.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-353f-x4gh-cqq8 is resolved across your whole dependency graph.

How do I detect GHSA-353f-x4gh-cqq8 in my RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nokogiri. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-353f-x4gh-cqq8 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-353f-x4gh-cqq8?

O3 pinpoints whether GHSA-353f-x4gh-cqq8 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-353f-x4gh-cqq8 actively exploited in the wild?

No public exploit code has been indexed for GHSA-353f-x4gh-cqq8 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 GHSA-353f-x4gh-cqq8 published, and has it been updated?

GHSA-353f-x4gh-cqq8 was published on July 21, 2025 and was last updated on February 4, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

GHSA-353f-x4gh-cqq8: Nokogiri patches vendored libxml2 to resol…

Blast Radius

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 v1.18.9 patches the vendored libxml2 to address CVE-2025-6021, CVE-2025-6170, CVE-2025-49794, CVE-2025-49795, and CVE-2025-49796.

Impact and severity

CVE-2025-6021

A flaw was found in libxml2's xmlBuildQName function, where integer overflows in buffer size calculations can lead to a stack-based buffer overflow. This issue can result in memory corruption or a denial of service when processing crafted input.

NVD claims a severity of 7.5 High (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/17d950ae

CVE-2025-6170

A flaw was found in the interactive shell of the xmllint command-line tool, used for parsing XML files. When a user inputs an overly long command, the program does not check the input size properly, which can cause it to crash. This issue might allow attackers to run harmful code in rare configurations without modern protections.

NVD claims a severity of 2.5 Low (CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L)

Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/5e9ec5c1

CVE-2025-49794

A use-after-free vulnerability was found in libxml2. This issue occurs when parsing XPath elements under certain circumstances when the XML schematron has the <sch:name path="..."/> schema elements. This flaw allows a malicious actor to craft a malicious XML document used as input for libxml, resulting in the program's crash using libxml or other possible undefined behaviors.

NVD claims a severity of 9.1 Critical (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H)

Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/81cef8c5

CVE-2025-49795

A NULL pointer dereference vulnerability was found in libxml2 when processing XPath XML expressions. This flaw allows an attacker to craft a malicious XML input to libxml2, leading to a denial of service.

NVD claims a severity of 7.5 High (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/62048278

CVE-2025-49796

A vulnerability was found in libxml2. Processing certain sch:name elements from the input XML file can trigger a memory corruption issue. This flaw allows an attacker to craft a malicious XML input file that can lead libxml to crash, resulting in a denial of service or other possible undefined behavior due to sensitive data being corrupted in memory.

NVD claims a severity of 9.1 Critical (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H)

Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/81cef8c5

Affected Versions

Nokogiri < 1.18.9 when using CRuby (MRI) with vendored libxml2

Patched Versions

Nokogiri >= 1.18.9

Mitigation

Upgrade to Nokogiri v1.18.9 or later.

Users who are unable to upgrade Nokogiri may also choose a more complicated mitigation: compile and link Nokogiri against patched external libxml2 libraries which will also address these same issues.

References

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`nokogiri`	all versions	1.18.9

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nokogiri. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update nokogiri to 1.18.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-353f-x4gh-cqq8 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-353f-x4gh-cqq8 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-353f-x4gh-cqq8. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Summary Nokogiri v1.18.9 patches the vendored libxml2 to address CVE-2025-6021, CVE-2025-6170, CVE-2025-49794, CVE-2025-49795, and CVE-2025-49796. ## Impact and severity ### CVE-2025-6021 A flaw was found in libxml2's xmlBuildQName function, where integer overflows in buffer size calculations can lead to a stack-based buffer overflow. This issue can result in memory corruption or a denial of service when processing crafted input. NVD claims a severity of 7.5 High (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/17d950ae

O3 Security · Impact-Aware SCA

Is GHSA-353f-x4gh-cqq8 in your dependencies?

O3 detects GHSA-353f-x4gh-cqq8 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

GHSA-353f-x4gh-cqq8