CVE-2026-79769
MEDIUMCVE-2026-79769 is a medium-severity (CVSS 5.5) CWE-843 vulnerability. O3 Security confirms whether CVE-2026-79769 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Nokogiri versions before 1.19.4 contain a possible invalid (out-of-bounds) memory read in the protected internal Node#initialize_copy_with_args helper behind Node#dup and #clone, which…
Description
Nokogiri versions before 1.19.4 contain a possible invalid (out-of-bounds) memory read in the protected internal Node#initialize_copy_with_args helper behind Node#dup and #clone, which unwrapped its source argument as an xmlNode without a type check. If application code calls this protected method with a non-Node argument (e.g., a Namespace), it reads an xmlNs out of bounds, crashing the process. This is only triggerable by a programming error and cannot be triggered by untrusted input or normal use of the public API. Only CRuby is affected. Version 1.19.4 adds a type check and raises TypeError.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. 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.
Remediation status
No patched version of the affected component has shipped for CVE-2026-79769 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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 CVE-2026-79769 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 CVE-2026-79769. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-79769 in your dependencies?
O3 detects CVE-2026-79769 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.