9.1

CVE-2026-87802: apache software foundation apache syncope

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

Vulnerability summary

CVE-2026-87802 is a critical (CVSS 9.1) vulnerability in apache software foundation apache syncope. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 18.7% 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
0.28%
0%100%
Low · +0.02 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

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.28%

Chance of exploitation in the next 30 days

Percentile

19%

Versus all other CVEs

30-day change

+0.02 pp

From 0.26% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.28%

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