CVE-2026-97666: Nexus Repository 3 - Unsafe Reflection in ExtDirect Repository Endpoint

Severity: medium (CVSS 6.9 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-15 · updated 2026-10-16
Weakness: CWE-470

Description

Sonatype Nexus Repository 3 allows an unauthenticated remote attacker to supply attacker-controlled input to a Java class loading call through an ExtDirect endpoint. This allows the attacker to learn whether specific classes are present in the application. The issue does not by itself allow code execution.

Affected products

Sonatype Nexus Repository 3: from 3.0.0 before 3.97.0 — fixed in 3.97.0

How to fix

Upgrade to a fixed version: Sonatype Nexus Repository 3 3.97.0. Check the vendor advisory for mitigations.

References

https://help.sonatype.com/en/sonatype-nexus-repository-3-97-0-release-notes.html
https://support.sonatype.com/hc/en-us/articles/56206649520147/

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