CVE-2026-42521

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.

Published: 2026-04-29 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-42521 is rated Low Risk (33.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.07%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-42521

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-07 0.04% 0.07% +0.04%
2 2026-04-30 — 0.04% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42521

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-42521

GitHub Security Advisory for CVE-2026-42521

GHSA-jp9r-mmhw-vff3 · Severity: medium · Ecosystem: maven — Jenkins Matrix Authorization Strategy Plugin: Unsafe deserialization allows invocation of parameterless constructors

Affected software / configurations for CVE-2026-42521

Vendor Product Version Raw CPE
jenkins matrix_authorization_strategy >= 2.1, < 3.2.10 cpe:2.3:a:jenkins:matrix_authorization_strategy:*:*:*:*:*:jenkins:*:*
jenkins matrix_authorization_strategy 2.0 cpe:2.3:a:jenkins:matrix_authorization_strategy:2.0:beta1:*:*:*:jenkins:*:*
jenkins matrix_authorization_strategy 2.0 cpe:2.3:a:jenkins:matrix_authorization_strategy:2.0:beta2:*:*:*:jenkins:*:*
jenkins matrix_authorization_strategy 2.0 cpe:2.3:a:jenkins:matrix_authorization_strategy:2.0:beta3:*:*:*:jenkins:*:*

References for CVE-2026-42521

cvelogic Threat Intelligence