Apache Syncope Improper JWT Signature Verification (3.0.0-M0~4.1.2)
CVE-2026-87802 Published on September 14, 2026
Apache Syncope: SRA OAuth2 JWT signature verification bypass
Improper verification of cryptographic signature vulnerability in Apache Syncope.
When SRA is configured for OAuth 2.0 without JWKS set URI assigned, an attacker can forge arbitrary JWTs to impersonate any user identity and permissions, gaining full access to services proxied by SRA.
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.
Vulnerability Analysis
CVE-2026-87802 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.
Weakness Type
Improper Verification of Cryptographic Signature
The software does not verify, or incorrectly verifies, the cryptographic signature for data.
Products Associated with CVE-2026-87802
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Affected Versions
Apache Software Foundation Apache Syncope:- Version 3.0.0-M0, <= 3.0.16 is affected.
- Version 4.0.0-M0, <= 4.0.7 is affected.
- Version 4.1.0-M0, <= 4.1.2 is affected.