SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-87785

Authentication bypass by spoofing vulnerability in Apache Syncope.

CRITICAL 9.1EPSS 0.51%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.51%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1
9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS
0.51% probability · 43th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-290
Source
security@apache.org
EPSS trend
0%3%5%19 September 2026: 0.51%19 September 202619 September 2026

EPSS 0.5% since 19 September 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.