Grav - Stored CSS Injection via Markdown Image resize() Action
Grav before 2.0.0 (affected through 2.0.0-rc.9 and the 2.0 branch) contains a stored CSS injection vulnerability in the Markdown image resize() media action. Prior media hardening rejects direct ?style= payloads and unsafe attribute() fallbacks, but the resize() action in Excerpts::processMediaActions() writes caller-controlled values directly into the image's styleAttributes. A lower-privileged content editor who can edit page Markdown can store a crafted image URL with semicolon-delimited CSS declarations in the resize parameters, which are rendered into the final attribute when a higher-privileged reviewer/admin views the page or preview. This does not require JavaScript execution but enables UI redress/overlay and content-manipulation attacks (e.g., a full-viewport fixed overlay). Fixed in 2.0.0.
CVE-2026-58657
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-58657
Grav
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "Grav",
"product": "Grav",
"versions": [
{
"status": "affected",
"version": "2.0.0-rc.9",
"lessThan": "2.0.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "2.0.0",
"versionType": "semver"
}
],
"packageURL": "pkg:composer/getgrav/grav",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-58657
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #12766 · Revision 1
- Added to Heist Feed
- Publisher date