---
title: "CVE-2026-87802: Apache Syncope - Authentication Bypass"
description: "Apache Syncope 3.0.0-M0 through 3.0.16, 4.0.0-M0 through 4.0.7, and 4.1.0-M0 through 4.1.2 contain an authentication bypass caused by improper verification of cryptographic signatures in OAuth 2.0 SRA configuration without JWKS URI, letting attackers forge JWTs to impersonate users and gain full access, exploit requires misconfigured OAuth 2.0 SRA without JWKS URI."
url: https://panop.io/threat-heartbeat/CVE-2026-87802/
---

# CVE-2026-87802 Apache Syncope - Authentication Bypass

Apache Syncope 3.0.0-M0 through 3.0.16, 4.0.0-M0 through 4.0.7, and 4.1.0-M0 through 4.1.2 contain an authentication bypass caused by improper verification of cryptographic signatures in OAuth 2.0 SRA configuration without JWKS URI, letting attackers forge JWTs to impersonate users and gain full access, exploit requires misconfigured OAuth 2.0 SRA without JWKS URI.

CVSS base score 9.1 /10

Critical

CISA KEV

Not listed

Public exploit

None known

EPSS

0.28% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-87802)

## Details

Type

Authentication Bypass

Impact

Broken Authentication

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Published

14 September 2026

Updated

15 October 2026

Weakness

[CWE-347](https://cwe.mitre.org/data/definitions/347.html)

## Vendor fix

Upgrade to versions 4.0.8 or 4.1.3 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-87802](https://nvd.nist.gov/vuln/detail/CVE-2026-87802)
- [http://www.openwall.com/lists/oss-security/2026/09/14/25](http://www.openwall.com/lists/oss-security/2026/09/14/25)
- [https://lists.apache.org/thread/gx83cootj00kn8hqd73x1bp8441np33d](https://lists.apache.org/thread/gx83cootj00kn8hqd73x1bp8441np33d)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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