CVE-2026-42841CWE-79

Grav: Stored XSS via Markdown media attribute() action in Grav CMS

Medium · published May 11, 2026

CVSS v4.0
6.9
EPSS
0%
Percentile
16.7
In the wild
Unconfirmed
What it is

Grav is a file-based Web platform. Prior to 2.0.0-beta.2, an authenticated user with page editing permissions can inject an executable JavaScript event-handler attribute into rendered image HTML through Grav's Markdown media action syntax. The issue is caused by Markdown image query parameters being converted into callable media actions. The public attribute() media method can be reached this way, allowing an editor to set an arbitrary HTML attribute name and value on the generated image element. This vulnerability is fixed in 2.0.0-beta.2.

The record
Technical detail
CVSS v4.0
6.9 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N
EPSS
0.00260 · 16.7th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-05-11T14:52Z
EPSS history
Timeline
  • 11 MAY 14:52Z
    Grav: Stored XSS via Markdown media attribute() action in Grav CMS
    cvelistv5