CVE-2026-87785CWE-290

CVE-2026-87785

Critical · published September 14, 2026

CVSS v3.1
9.1
EPSS
1%
Percentile
45.2
In the wild
Unconfirmed
What it is

Authentication bypass by spoofing vulnerability in Apache Syncope.

When the configured JWKS settings for internal JWT authentication are disclosed (at least protocol and key), an attacker can spoof another user's privileges after completing a successful authentication and obtaining a valid JWT.

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.

The record
Technical detail
CVSS v3.1
9.1 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00549 · 45.2th percentile
Weakness
CWE-290 · Authentication Bypass by Spoofing
Published
2026-09-14T15:17Z
References (2)
https://lists.apache.org/thread/3t3om8mny7ng52q053pdzpmtdtosnqoo · [email protected]http://www.openwall.com/lists/oss-security/2026/09/14/24 · af854a3a-2127-422b-91ae-364da2661108
EPSS history
Timeline
  • 17 SEP 03:33Z
    EPSS moved — → 1%
    epss
  • 14 SEP 10:38Z
    Apache Syncope: JWT subject spoofing
    cvelistv5