What is CVE-2026-2736?

CVE-2026-2736 is a medium-severity vulnerability in Alkacon Opencms, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-02-19.

How severe is CVE-2026-2736?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Alkacon Opencms

CVE-2026-2736

Reflected Cross-site Scripting (XSS) in Alkacon's OpenCms v18.0, which allows an attacker to execute JavaScript code in the victim's browser by sending the victim a malicious URL containing the ‘q’ parameter in ‘/search/index.html’. This vulnerability can be exploited to steal sensitive user information such as session cookies, or to perform actions while impersonating the user.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.001 (4.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Alkacon Opencms — versions 18.0.0, 18.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

cve-coordination@incibe.es (Third Party Advisory, patch)

Frequently asked questions

What is CVE-2026-2736?: CVE-2026-2736 is a medium-severity vulnerability in Alkacon Opencms, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-02-19.
How severe is CVE-2026-2736?: Medium severity. CVSS v3 base score is 6.1 out of 10.