CVSS v3
9.1
CRITICAL
EPSS Score
0.3 %
exploit probability, as of 2026-09-28
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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.
Technical details
- Published
- 2026-09-14
- Last Modified
- 2026-09-14
Frequently asked questions
What is CVE-2026-87802?
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.
Is CVE-2026-87802 actively exploited?
Active exploitation of CVE-2026-87802 has not been confirmed. Its EPSS score was 0.3% on 2026-09-28, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2026-87802?
CVE-2026-87802 has a CVSS v3 base score of 9.1 (CRITICAL severity).
Is CVE-2026-87802 affecting your environment?
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