CVE-2026-48919

Jenkins Active Directory Plugin 2.41 and earlier follows LDAP referrals from the configured Active Directory server by default. These can forward to an RMI URL that causes Jenkins to deserialize attacker-controlled data, resulting in Remote Code Execution (RCE) on the Jenkins controller if deserialization "gadgets" are available on the classpath.

This allows attackers able to control the configured Active Directory server, or able to perform a machine-in-the-middle attack, to execute code on the Jenkins controller.

Active Directory Plugin 2.41.1 no longer follows LDAP referrals by default.

Administrators unable to update to a fixed version can start Jenkins with the Java system property hudson.plugins.active_directory.referral.ignore set to true to mitigate the vulnerability.

Administrators of Jenkins controllers requiring following LDAP referrals can set the Java system property hudson.plugins.active_directory.referral.ignore to false to restore the previous behavior.

Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect. Typical impact: arbitrary code execution or logic abuse.

CVE-2026-48919 has a CVSS score of 6.6 (Medium). The vector is network-reachable, high privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.41.1); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-48919? CVE-2026-48919 is a medium-severity insecure deserialization vulnerability in org.jenkins-ci.plugins:active-directory (maven), affecting versions < 2.41.1. It is fixed in 2.41.1. Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect.
2. How severe is CVE-2026-48919? CVE-2026-48919 has a CVSS score of 6.6 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of org.jenkins-ci.plugins:active-directory are affected by CVE-2026-48919? org.jenkins-ci.plugins:active-directory (maven) versions < 2.41.1 is affected.
4. Is there a fix for CVE-2026-48919? Yes. CVE-2026-48919 is fixed in 2.41.1. Upgrade to this version or later.
5. Is CVE-2026-48919 exploitable, and should I be worried? Whether CVE-2026-48919 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-48919 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-48919? Upgrade org.jenkins-ci.plugins:active-directory to 2.41.1 or later.