CVE-2026-87802 json
Apache Syncope: SRA OAuth2 JWT signature verification bypass
published 2026-09-14 55 d ago modified 2026-09-14 55 d ago also EUVD-2026-77358
- cvss
- 9.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 20%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 55 d ago
Exploit prediction
0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| CNA | 3.1 | 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
Affected products
- Apache Software Foundation Apache Syncope
Classification
- Weakness
-
- CWE-347 Improper Verification of Cryptographic Signature
References
Sources
- CVE List CVE-2026-87802
- NVD CVE-2026-87802
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