Vulnerability · Published Jul 15, 2026 · Assigned by VulnCheck

CVE-2026-61453Grav before 2.0.1 XSS via Twig String Concatenation

Medium 6.1

In plain English

A medium-severity cross-site scripting in grav from getgrav. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.1Medium

Exploit odds (30 days)0.2%top 90.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	getgrav/grav	2.0.1	GHSA-2c4f-86xc-cr74

Affected products (as reported)

Vendor	Product	Versions
getgrav	grav	0 – before 2.0.1

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

References

GitHub Security Advisory (GHSA-2c4f-86xc-cr74) vendor-advisory
VulnCheck Advisory: Grav before 2.0.1 XSS via Twig String Concatenation third-party-advisory