{"id":"CVE-2026-57434","aliases":["GHSA-9cv2-cfxc-v4v2"],"url":"https://o3.security/vulnerability/CVE-2026-57434","summary":"Nokogiri: Null Pointer Dereference calling methods on uninitialized wrapper classes","details":"### Summary\n\nNokogiri contains a bug when calling certain methods on allocated-but-uninitialized native wrapper classes that inherit from `Nokogiri::XML::Node`. This caused a NULL pointer dereference that could crash the process.\n\nNokogiri 1.19.4 checks for missing native data pointers and raises a `RuntimeError`.\n\nJRuby is not affected.\n\n### Severity\n\nThe Nokogiri maintainers have evaluated this as low severity. This is only triggered by a programming error. It requires application code to call `.allocate` directly on a native-backed class and then invoke methods on the resulting uninitialized object. It cannot be triggered by untrusted input or through normal use of the public API.\n\n### Mitigation\n\nUpgrade to Nokogiri 1.19.4 or later.\n\nAvoid calling `.allocate` directly on Nokogiri native-backed classes. Use the documented constructors and factory methods instead.\n\n### Credit\n\nThis issue was responsibly reported by Zheng Yu from depthfirst.com.","published":"2026-06-25T14:32:10.604Z","modified":"2026-10-21T02:58:44.647679267Z","cvss":null,"epss":{"score":0.0046,"percentile":0.38993,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"RubyGems","name":"nokogiri","fixedVersion":"1.19.4"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57434.json"},{"type":"ADVISORY","url":"https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-9cv2-cfxc-v4v2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-57434"},{"type":"PACKAGE","url":"https://github.com/sparklemotion/nokogiri"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-21T02:58:44.647679267Z"}}