XSS in Getgrav Grav
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (15.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 15.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Getgrav Grav — versions 0
Weakness classification (CWE)
References
- github.com/getgrav/grav/security/advisories/GHSA-q5fw-vpqc-fgph (vendor-advisory)
- www.vulncheck.com/advisories/grav-stored-cross-site-scripting-via-shortcode-att… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-64628?
- CVE-2026-64628 is a medium-severity vulnerability in Getgrav Grav, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-07-21.
- How severe is CVE-2026-64628?
- Medium severity. CVSS v3 base score is 5.4 out of 10.