XSS in Getsimple-Ce Getsimple Cms

CVE-2026-26351

GetSimpleCMS Community Edition (CE) versions prior to 3.3.22 (3.3.16 tested) contains a stored cross-site scripting (XSS) vulnerability in the Theme to Components functionality within components.php. User-supplied input provided to the "slug" field of a component is stored without proper output encoding. While other fields are sanitized using safe_slash_html(), the slug parameter is written to XML and later rendered in the administrative interface without sanitation, resulting in persistent execution of arbitrary JavaScript. An authenticated administrator can inject malicious script content that executes whenever the affected Components page is viewed by any authenticated user, enabling session hijacking, unauthorized administrative actions, and persistent compromise of the CMS administrative interface.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.003 (21.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-26351?
CVE-2026-26351 is a medium-severity vulnerability in Getsimple-Ce Getsimple Cms, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2026-02-24.
How severe is CVE-2026-26351?
Medium severity. CVSS v3 base score is 4.8 out of 10.