What is CVE-2026-53421?

CVE-2026-53421 is a critical-severity vulnerability in Apache Software Foundation Syncope, classified under CWE-653. CVSS score: 9.8/10. Published 2026-07-20.

How severe is CVE-2026-53421?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Apache Software Foundation Syncope

CVE-2026-53421

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)…

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Apache Software Foundation Syncope — versions 3.0.0-M0, 4.0.0-M0, 4.1.0-M0

Weakness classification (CWE)

CWE-653

References

security@apache.org (vendor-advisory)
af854a3a-2127-422b-91ae-364da2661108

Frequently asked questions

What is CVE-2026-53421?: CVE-2026-53421 is a critical-severity vulnerability in Apache Software Foundation Syncope, classified under CWE-653. CVSS score: 9.8/10. Published 2026-07-20.
How severe is CVE-2026-53421?: Critical severity. CVSS v3 base score is 9.8 out of 10.