CVE-2026-87802

EUVD-2026-77358
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
apacheCNA
9.1 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
apachesyncope
𝑥
≤ 3.0.16
CNA
apachesyncope
𝑥
≤ 4.0.7
CNA
apachesyncope
𝑥
≤ 4.1.2
CNA
Common Weakness Enumeration
References
https://lists.apache.org/thread/gx83cootj00kn8hqd73x1bp8441np33d
http://www.openwall.com/lists/oss-security/2026/09/14/25