Jenkins Matrix Auth Strategy Plugin arbitrary cls inst (CVE-2026-42521)
CVE-2026-42521 Published on April 29, 2026
Jenkins Matrix Authorization Strategy Plugin 2.0-beta-1 through 3.2.9 (both inclusive) invokes parameterless constructors of classes specified in configuration when deserializing inheritance strategies, without restricting the classes that can be instantiated, allowing attackers with Item/Configure permission to instantiate arbitrary types, which may lead to information disclosure or other impacts depending on the classes available on the classpath.
Vulnerability Analysis
CVE-2026-42521 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity, and no impact on availability.
Weakness Type
What is a Marshaling, Unmarshaling Vulnerability?
The application deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
CVE-2026-42521 has been classified to as a Marshaling, Unmarshaling vulnerability or weakness.
Products Associated with CVE-2026-42521
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Affected Versions
Jenkins Project Jenkins Matrix Authorization Strategy Plugin:- Version 2.0-beta-1, <= 3.2.9 is affected.