CVE-2026-87802

Apache Syncope: SRA OAuth2 JWT signature verification bypass

Published Sep 14, 2026 CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Apache
Apache syncope
Vendors & Products Apache
Apache syncope
Type Values Removed Values Added
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.
Title Apache Syncope: SRA OAuth2 JWT signature verification bypass
Weaknesses CWE-347
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
apache
Published
Updated
Sep 14, 2026, 7:39 PM
Reserved
Sep 9, 2026, 10:11 AM
Status
Deferred
Published
Sep 14, 2026, 11:17 AM
Modified
Sep 14, 2026, 8:58 PM