CVE-2026-26351: GetSimpleCMS-CE < 3.3.22 Stored XSS via components.php
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 safeslashhtml(), 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
GetSimpleCMS Community Edition (CE)to a version that resolves this vulnerability.Fixed in 3.3.22 - Compensating control
Restrict access to the CMS administrative interface/components page to trusted authenticated users until the CMS is upgraded to 3.3.22, to limit the impact of the stored XSS.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-26351?
CVE-2026-26351 has a severity rating that indicates a moderate risk to applications using GetSimpleCMS Community Edition version 3.3.16.
How do I fix CVE-2026-26351?
To fix CVE-2026-26351, update to the latest version of GetSimpleCMS Community Edition that addresses the stored XSS vulnerability.
What types of inputs are affected by CVE-2026-26351?
CVE-2026-26351 is specifically affected by user-supplied input in the 'slug' field of components in GetSimpleCMS.
What does CVE-2026-26351 allow an attacker to do?
CVE-2026-26351 allows an attacker to inject malicious scripts through the Theme to Components functionality, leading to stored cross-site scripting attacks.
Which version of GetSimpleCMS is impacted by CVE-2026-26351?
CVE-2026-26351 impacts GetSimpleCMS Community Edition version 3.3.16 and earlier versions.