Grav before 2.0.20 Cross-Site Scripting via Assets Sandbox
CVE-2026-86197

5.1MEDIUM

Key Information:

Vendor

Getgrav

Status
Grav
Vendor
CVE Published:
5 September 2026

What is CVE-2026-86197?

Grav before 2.0.20 contains a cross-site scripting vulnerability in the Twig sandbox policy that allowlists addJs and addCss methods on Grav\Common\Assets without proper output escaping. Page editors can inject arbitrary script by registering malicious assets or injecting attributes, which are rendered unescaped into document head tags and executed for all visitors including administrators.

Affected Version(s)

grav 0 < 2.0.20

grav 2.0.20

References

https://github.com/getgrav/grav/security/advisories/GHSA-...
vendor-advisory
https://www.vulncheck.com/advisories/grav-before-2.0.20-c...
third-party-advisory

CVSS V4

Score:
5.1
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

skeletonsec
.