CVE-2026-87785: Apache Software Foundation Apache Syncope

Critical severity, CVSS 9.1. EPSS: 0.5% chance of exploitation in the next 30 days.

Authentication bypass by spoofing vulnerability in Apache Syncope. When the configured JWKS settings for internal JWT authentication are disclosed (at least protocol and key), an attacker can spoof another user's privileges after completing a successful authentication and obtaining a valid JWT. This issue affects Apache Syncope: from 3.0.0-M0 through 3.0.16, from 4.0.0-M0 through 4.0.7, from 4.1.0-M0 through 4.1.2. Users are recommended to upgrade to version 4.0.8 / 4.1.3, which fix this issue.

Affected products

• Apache Software Foundation Apache Syncope: from 3.0.0-M0, up to and including 3.0.16; from 4.0.0-M0, up to and including 4.0.7; from 4.1.0-M0, up to and including 4.1.2

Published 2026-09-14. Last modified 2026-09-14.