🚨 [security] Update nokogiri 1.19.2 → 1.19.3 (patch)

[depfu]

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🚨 Your current dependencies have known security vulnerabilities 🚨

This dependency update fixes known security vulnerabilities. Please see the details below and assess their impact carefully. We recommend to merge and deploy this as soon as possible!

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Here is everything you need to know about this update. Please take a good look at what changed and the test results before merging this pull request.

What changed?

↗️ nokogiri (indirect, 1.19.2 → 1.19.3) · Repo · Changelog

Security Advisories 🚨

🚨 Nokogiri CSS selector tokenizer has regular expression backtracking

Summary

Nokogiri's CSS selector tokenizer contains regular expressions whose construction may result in exponential regex backtracking on adversarial selectors. Three ReDoS vectors are addressed in this release:

1. String-literal tokenization on certain unterminated quoted-string input.
2. String-literal tokenization on a separate class of hex-escape-rich input.
3. Identifier tokenization on hex-escape-rich input.

The public CSS selector methods that funnel through the affected tokenizer are Nokogiri::CSS.xpath_for, Node#css, Node#at_css, Searchable#search, and CSS::Parser#parse.

Mitigation

Upgrade to Nokogiri >= 1.19.3.

If users are unable to upgrade, two options are available:

• Avoid the use of attacker-controlled text in CSS selectors. Applications that only pass developer-authored selectors to Nokogiri are not directly exposed.
• Set global Regexp.timeout (Ruby 3.2+, JRuby 9.4+) to bound parse time.

Severity

The Nokogiri maintainers have evaluated this as High Severity (CVSS 7.5, AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

An attacker able to inject user-supplied text into a CSS selector parse method can cause exponential backtracking, resulting in a potential denial of service.

Resources

• CWE-1333: Inefficient Regular Expression Complexity

Credit

Vector 1 was responsibly reported by @colby-swandale. Vectors 2 and 3 were discovered by @flavorjones during the response to the original report.

🚨 Nokogiri XSLT transform has a memory leak

Summary

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.

Release Notes

1.19.3

v1.19.3 / 2026-04-27

Fixed / Security

• Address exponential regex backtracking in CSS selector tokenizer. See GHSA-c4rq-3m3g-8wgx for more information.
• [CRuby] Address memory leak in XSLT::Stylesheet#transform. See GHSA-v2fc-qm4h-8hqv for more information.

sha256 checksums

46b89e5d7b9e844c2ee360794240c6ea2a4e6fa0c5892a4ed487db621224b639  nokogiri-1.19.3-aarch64-linux-gnu.gem
8392dfdcd21be7a94dbbe9ccc138dea01b97b24cb2dc02a114ca98bfb1d9a0b7  nokogiri-1.19.3-aarch64-linux-musl.gem
3919d5ffc334ad778a4a9eb88fda7dcb8b1fb58c8a52ac640c6dcd2f038e774f  nokogiri-1.19.3-arm-linux-gnu.gem
9ce1cb6346bb9c67b1550eb537aa183ead91e4b6eadb2f36ade02d8dd2a79fb6  nokogiri-1.19.3-arm-linux-musl.gem
71b9bd424b1b7abc18b05052a1a3cfd3627abdca62be280854cc411791357e42  nokogiri-1.19.3-arm64-darwin.gem
40ea6ebf5cf2005dae1dee26dd557d3afb41fb6de6c9764aca8cf06fdb841db1  nokogiri-1.19.3-java.gem
8bb7132cad356c879a1286eaabcb5e68326cb2490317984280fbc62f456d506a  nokogiri-1.19.3-x64-mingw-ucrt.gem
77f3fba57d46c53ab31e62fc6c28f705109d1bf6264356c76f132b2be5728d4d  nokogiri-1.19.3-x86_64-darwin.gem
2f5078620fe12e83669b5b17311b32532a8153d02eee7ad06948b926d6080976  nokogiri-1.19.3-x86_64-linux-gnu.gem
248c906d2166eca5efb56d52fdee5f9a1f51d69a72e2b64fdac647b4ce39ea3f  nokogiri-1.19.3-x86_64-linux-musl.gem
78312cbac32a40c812780d9678221b79d51288eec00054c1a8d15f7ce05960e8  nokogiri-1.19.3.gem

Does any of this look wrong? Please let us know.

Commits

See the full diff on Github. The new version differs by 10 commits:

• version bump to v1.19.3
• fix: backtracking in CSS tokenizer rules (v1.19.x backport) (#3627)
• test: skip CSS tokenizer benchmarks on JRuby
• fix: ReDoS in CSS tokenizer ident rule
• fix: ReDoS in CSS tokenizer STRING rule
• fix: memory leak in XSLT transform (backport to v1.19.x) (#3624)
• doc: update CHANGELOG
• fix: memory leak in XSLT transform
• dep(test): test against libxml-ruby v6 (#3618)
• doc: add security warnings for untrusted XSLT stylesheets

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