Which versions of PHP are affected by CVE-2026-26351?

CVE-2026-26351 presents moderate security risk, a cross-site scripting vulnerability rated CVSS 4.8. Attackers could inject scripts to steal sessions or perform actions as authenticated users.

How to fix or mitigate CVE-2026-26351?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

PHP CVE-2026-26351

Q: What is the CVSS score of CVE-2026-26351?

CVE-2026-26351 has a CVSS 4.0 base score of 4.8 (Medium). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2026-02-24 disclosure@vulncheck.com

PHP XSS Getsimple Cms

4.8

CVSS 4.0 · Vendor: vulncheck

Severity by source

Vendor (vulncheck) PRIMARY

4.8 MEDIUM

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from Vendor (vulncheck) · only source for this CVE.

CVSS VectorVendor: vulncheck

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

Scope

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

CVE Published

Feb 24, 2026 - 23:16 nvd

MEDIUM 4.8

DescriptionCVE.org

GetSimpleCMS Community Edition (CE) version 3.3.16 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.

AnalysisAI

Stored XSS in GetSimpleCMS Community Edition 3.3.16 allows authenticated administrators to inject malicious JavaScript through the component slug field, which persists in XML storage and executes when other users access the Components page. An attacker with admin privileges can exploit this to hijack sessions, perform unauthorized administrative actions, and persistently compromise the CMS interface for all authenticated users. The vulnerability affects PHP-based GetSimpleCMS installations and currently has no available patch.

Technical ContextAI

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects the Theme to component of Getsimple Cms. GetSimpleCMS Community Edition (CE) version 3.3.16 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 JavaScr

RemediationAI

Monitor vendor advisories for a patch. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.