CVE-2026-70426
CRITICALCVE-2026-70426 is a critical-severity (CVSS 9) Deserialization of Untrusted Data vulnerability. O3 Security confirms whether CVE-2026-70426 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
In Remoting 3384.v60d89463d9e0 and earlier, except 3355.3357.v931d3c992987, included in Jenkins 2.575 and earlier, LTS 2.568.1 and earlier, the JEP-200 class filter is not applied to…
Description
In Remoting 3384.v60d89463d9e0 and earlier, except 3355.3357.v931d3c992987, included in Jenkins 2.575 and earlier, LTS 2.568.1 and earlier, the JEP-200 class filter is not applied to classes resolved via a fallback path in the Remoting deserialization implementation, allowing agent processes, code running on agents, and attackers with Agent/Connect permission to bypass the JEP-200 deserialization filter for classes on the Jenkins core classpath.
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-2026-70426 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-2026-70426 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-2026-70426. 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-2026-70426 in your dependencies?
O3 detects CVE-2026-70426 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.