Review reviewCritical

CVE-2026-53421

Apache Software Foundation Apache Syncope, syncope

Improper Isolation or Compartmentalization vulnerability in Apache Syncope. An administrator with adequate entitlements can achieve remote code execution through the connector subsystem by relying on scripted connectors' (REST and SQL) capability to run Groovy scripts. This issue affects Apache Syncope: from 3.0.0-M0 through 3.0.16, from 4.0.0-M0 Through 4.0.6, from 4.1.0-M0 through 4.1.1. Users are recommended to upgrade to version 4.0.7 / 4.1.2, which fix this issue by hardening the Groovy security sandbox.

CVSS: 9.8
EPSS: 0.68%
CISA KEV: Not listed
Published: 2026.07.21

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.68%

Technical severityCVSS 9.8

Vulnerability overview

Affected product and versions

Product: Apache Software Foundation Apache Syncope, syncope
Affected versions: >= 3.0.0-M0 <= 3.0.16, >= 4.0.0-M0 <= 4.0.6, >= 4.1.0-M0 <= 4.1.1, >= 3.0.0 <= 3.0.16, >= 4.0.0 < 4.0.7, >= 4.1.0 < 4.1.2
Fixed versions: 4.0.7, 4.1.2

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Apache Software Foundation Apache Syncope, syncope and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE: CWE-653