CVE-2026-87802

Apache Syncope: SRA OAuth2 JWT signature verification bypass

State: Published
Severity: 9.1 Critical
Published: Sep 14, 2026
Updated: Sep 14, 2026
Reserved: Sep 9, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	9.1 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N	CISA-ADP

Weaknesses

CWE-347 Improper verification of cryptographic signature

Affected Products

Product	Versions
Apache SyncopeApache Software Foundation	3.0.0-M0 through 3.0.16Affected 4.0.0-M0 through 4.0.7Affected 4.1.0-M0 through 4.1.2Affected

References

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