CVE-2026-87802

Critical

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.

SeverityCritical

CVSS9.1

Exploit probability—

ProductApache Syncope

PublishedSep 14, 2026

First seenSep 14, 2026

Weakness typeCWE-347CWE-347

How to fix

Vendor advisories

lists.apache.org/thread/gx83cootj00kn8hqd73x1bp8441np33d

Affected products

Product	Affected versions	Fixed in
Apache Software Foundation Apache Syncope	3.0.0-M0 ≤ v ≤ 3.0.16, 4.0.0-M0 ≤ v ≤ 4.0.7, 4.1.0-M0 ≤ v ≤ 4.1.2	—

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