Script Security Plugin EUVD-2026-80749

Requires an authenticated Jenkins user holding permission to define and run sandboxed scripts, including Pipelines (typically Job/Configure or equivalent script-submission rights) on an instance running Script Security Plugin 1415.v9a_f9b_3a_c253d or earlier. No user interaction or non-default configuration is needed beyond the standard sandbox/Pipeline feature being usable by the attacker; the sandbox itself is the control being bypassed. The limiting factor is the account permission (PR:L) - anonymous or read-only users without script-execution rights cannot trigger it - making this an authenticated sandbox-to-RCE escalation rather than a fully unauthenticated remote exploit.

This is a genuine high-priority vulnerability, not CVSS inflation. The provided vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (8.8) describes a network-reachable, low-complexity sandbox escape that yields arbitrary code execution in the Jenkins controller JVM - the crown jewel of a CI/CD environment (credentials, secrets, build agents, deployment keys). PR:L is accurate and material: the attacker needs a valid Jenkins account holding permission to define and run sandboxed scripts/Pipelines (e.g., Job/Configure or Overall/Read plus workspace access), so this is an authenticated privilege-escalation from a constrained sandbox to full controller RCE rather than a pure anonymous exploit. No EPSS, KEV, POC, or SSVC data was supplied, so exploitation status is 'no public exploit identified at time of analysis'; absence of these signals is not evidence of low risk, because Script Security sandbox bypasses are a recurring, heavily weaponized class in Jenkins and the technique (a rejected-annotation gap) is straightforward to reproduce from the advisory. One caveat worth verifying: the vendor scores scope S:U, but escaping a sandbox to execute in the controller JVM arguably crosses a security authority boundary (S:C) - this does not change the operational severity but is noted for transparency.

An attacker who already holds a low-privileged Jenkins account with permission to create and run a sandboxed Pipeline submits a Groovy script bearing the @GroovyASTTransformationClass annotation, which the plugin fails to reject. At Groovy compile time the attached AST transformation executes outside the sandbox, running arbitrary Java/Groovy in the controller JVM and letting the attacker dump stored credentials, pivot to build agents, or take over the Jenkins instance. No public exploit is identified at time of analysis, but the mechanism is fully described in the advisory and trivially reproducible.