CVE-2026-64628: XSS (CVSS 5.4)

Description

Grav contains a stored cross-site scripting vulnerability in shortcode-core attribute handlers where the XSS detection scan only matches payloads containing literal angle brackets, allowing shortcode parameters to bypass validation. Attackers with admin.pages permission can inject malicious JavaScript through shortcode attributes that execute in any viewer's browser, including administrators, enabling session hijacking via admin nonce theft.

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CVSS v3.1 Score

5.4

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://github.com/getgrav/grav/security/advisories/GHSA-q5fw-vpqc-fgph https://www.vulncheck.com/advisories/grav-stored-cross-site-scripting-via-shortcode-attribute-handlers

Frequently Asked Questions

What is CVE-2026-64628? +

Grav contains a stored cross-site scripting vulnerability in shortcode-core attribute handlers where the XSS detection scan only matches payloads containing literal angle brackets, allowing shortcode parameters to bypass validation. Attackers with admin.pages permission can inject malicious JavaScript through shortcode attributes that execute in any viewer's browser, including administrators, enabling session hijacking via admin nonce theft. It has a CVSS v3.1 base score of 5.4 (MEDIUM).

How severe is CVE-2026-64628? +

CVE-2026-64628 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

How do I check if I'm vulnerable to CVE-2026-64628? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2026-64628