Is CVE-2026-42521 in the CISA KEV catalog?

No. CVE-2026-42521 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-42521?

CVE-2026-42521 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2026-42521?

CVE-2026-42521 has an EPSS score of 0.25% (16th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-42521?

Upgrade matrix authorization strategy to 3.2.10 or later.

CVE & CISA-KEV Catalog

CVE-2026-42521

MEDIUM

6.5

CVSS v3

NVD

Description

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.

CWE-502Deserialization of Untrusted Data

How to fix

Remediation Available

matrix authorization strategyNVD

Affected:>= 2.1, < 3.2.10Fixed in:3.2.10CVE-2026-42521derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Exploit Intelligence

0.25%probability of exploitation in 30 days

16thpercentile

Low risk: more likely to be exploited than 16% of all known CVEs.

References

Vendor Advisory1

jenkins.io

Related Vulnerabilities

Other CWE-502 (Deserialization of Untrusted Data) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-0669	High	7.2	100%	KEV + Ransom	Fix
CVE-2021-44228	Critical	10.0	100%	KEV + Ransom	Fix
CVE-2021-35464	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2023-29300	Critical	9.8	100%	KEV + Ransom	-
CVE-2025-53770	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2022-47986	Critical	9.8	100%	KEV + Ransom	-

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-06.