CVE-2026-23794 Apache Syncope: Reflected XSS on Enduser Login

What is CVE-2026-23794?

CVE-2026-23794 is a medium-severity cross-site scripting vulnerability in Apache Syncope, published on 3 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

Reflected XSS in Apache Syncope's Enduser Login page. An attacker that tricks a legitimate user into clicking a malicious link and logging in to Syncope Enduser could steal that user's credentials.

This issue affects Apache Syncope: from 3.0 through 3.0.15, from 4.0 through 4.0.3.

Users are recommended to upgrade to version 3.0.16 / 4.0.4, which fix this issue.

Weakness: CWE-79

Which versions are affected by CVE-2026-23794?

4 open source packages ship an affected version, including org.apache.syncope.client.idrepo:syncope-client-idrepo-common-ui. It affects 1 product.

Products include Apache Syncope.

How do I fix CVE-2026-23794?

Upgrade org.apache.syncope.client.idrepo:syncope-client-idrepo-common-ui to a fixed version for your release line: 3.0.16 or 4.0.4.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-23794 being exploited?

There is no known exploitation of CVE-2026-23794 in the wild and no public exploit code.

Other vulnerabilities in Apache Syncope

• CVE-2026-53405 Apache Syncope: Remote Code Execution via Flowable BPMN Groovy ScriptTask Critical 9.8
• CVE-2026-53421 Apache Syncope: Remote Code Execution via Scripted Connector Critical 9.8
• CVE-2026-57308 Apache Syncope: SQL injection vulnerability in Audit Events search Critical 9.8
• CVE-2026-62183 Apache Syncope: User self-service privilege escalation Critical 9.8
• CVE-2026-63071 Apache Syncope: RCE via Groovy Sandbox bypass Critical 9.8

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-v84m-gfw5-hm2w.