XSS in Getgrav Grav
CVE-2026-61453
Grav v2.0.0 contains a cross-site scripting vulnerability (fixed in 2.0.1). The XSS blueprint validator (Security::detectXss()) runs on raw page content before Twig processing. When Twig content processing is enabled (twig_content.process_enabled: true), an attacker with page-write API permission can use Twig's string concatenation operator (~) to dynamically construct event handler names, dangerous tag names, or dangerous protocols at render time (e.g. {% set x = "on" ~ "error" %}). The validator sees only the harmless Twig expression and allows the content, but after Twig rendering the output (rendered via {{ page.content|raw }}) contains an active payload such as <img src=1 onerror=alert(1)>, executing arbitrary JavaScript in visitors' browsers.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (8.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 8.8% 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: 0.002 · change: -0.001
Affected products
- Getgrav Grav — versions 0, 2.0.1
Weakness classification (CWE)
References
- github.com/getgrav/grav/security/advisories/GHSA-2c4f-86xc-cr74 (vendor-advisory)
- www.vulncheck.com/advisories/grav-before-xss-via-twig-string-concatenation (third-party-advisory)
Frequently asked questions
- What is CVE-2026-61453?
- CVE-2026-61453 is a medium-severity vulnerability in Getgrav Grav, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-07-15.
- How severe is CVE-2026-61453?
- Medium severity. CVSS v3 base score is 6.1 out of 10.