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)
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.003 (16.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 16.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.003 · change: +0.001
Affected products
- Alkacon Opencms — versions 18.0.0, 18.0
Weakness classification (CWE)
References
- www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-alkacons-op… (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.