9.1

CVE-2026-87785: apache software foundation apache syncope Authentication Bypass by Spoofing

CVSS: 9.1v3.1CriticalDeferred
Published 14-09-2026Last modified 14-09-2026
Open JSON

Vulnerability summary

CVE-2026-87785 is a critical (CVSS 9.1) Authentication Bypass by Spoofing vulnerability in apache software foundation apache syncope. EPSS estimates a 0.55% chance of exploitation in the next 30 days, higher than 44.7% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.1/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.55%
0%100%
Low · +0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 14-09-2026
    PublishedVulnerability first disclosed.
  2. 14-09-2026
    Last modifiedVulnerability information updated.

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 metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.55%

Chance of exploitation in the next 30 days

Percentile

45%

Versus all other CVEs

30-day change

+0.04 pp

From 0.51% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.55%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Apache software foundation1 product
  • apache syncope≥ 3.0.0-M0, ≤ 3.0.16 | ≥ 4.0.0-M0, ≤ 4.0.7 | ≥ 4.1.0-M0, ≤ 4.1.2

1 vendor · 1 product

References

2 links