XSS in Wso2 API Control Plane

CVE-2026-4103

Insufficient HTML sanitization in the Publisher Portal and Developer Portal allows untrusted user input to be rendered without proper encoding or neutralization. This enables the injection and execution of malicious JavaScript when affected API documents are viewed. Successful exploitation may result in the execution of malicious scripts within the user's browser context when viewing API documentation. Users with permissions to access the API documentation through these portals may be impacted, potentially allowing attackers to perform actions on behalf of the user, depending on their session privileges.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (22.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-4103: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-4103?
CVE-2026-4103 is a medium-severity vulnerability in Wso2 API Control Plane, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-09-14.
How severe is CVE-2026-4103?
Medium severity. CVSS v3 base score is 6.4 out of 10.