CVE-2026-53435 remediation guide
Jenkins Project Jenkins, OpenShift Developer Tools and Services, jenkins
In Jenkins 2.567 and earlier, LTS 2.555.2 and earlier, it is possible for attackers to have Jenkins deserialize arbitrary types defined in Jenkins core or plugins from an attacker-controlled `config.xml` submission in a way that allows them to handle HTTP requests afterwards. This can be used to impersonate any user and send HTTP requests on their behalf, up to and including use of the Script Console to run arbitrary code, or to read arbitrary files from the Jenkins controller.
Identify the affected asset
Confirm whether Jenkins Project Jenkins, OpenShift Developer Tools and Services, jenkins is installed, record the deployed version and installation path, and identify exposed interfaces.
- Record the product name, package or appliance identifier, and installed version.
- Identify internet-facing, administrative, API, and internal access paths.
- Preserve the pre-change configuration and relevant service logs.
Validate the affected-version match
Compare the deployed version with the affected range: < 2.555.3, < 2.568. Treat incomplete inventory results as unresolved.
Prioritize with independent signals
FIRST EPSS indicates an elevated probability of exploitation. Combine this signal with asset criticality, exposure, compensating controls, and business impact.
Apply supported remediation
Follow the vendor advisory or supported update path. Current fixed-version status: 2.555.3, 2.568. Preserve configuration and rollback material before change.
Verify the result
Confirm the resulting version, service health, authentication and access paths, monitoring coverage, and relevant security logs.
- Confirm the expected version and package state.
- Run a functional health check for critical service paths.
- Review authentication, error, application, and security monitoring logs.
- Reassess exposure if the supported fix cannot be applied.
Operational boundary
This page does not replace the vendor advisory, support contract, change-management process, or recovery plan. Do not infer that an asset is unaffected from an incomplete inventory query or a missing fixed-version field.