Vulnerability · Published Jul 10, 2026 · Assigned by GitHub_M

CVE-2026-55890Grav: Stored CSS injection via Markdown image ?style=… reaches MediaObjectTrait::style()

Medium 4.8

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 0.5% (higher than 43% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.8Medium

Exploit odds (30 days)0.5%top 56.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Grav is a file-based Web platform. Prior to 2.0.0-rc.9, Grav's incomplete fix for stored XSS through the Markdown media attribute action (CVE-2026-42841) leaves the sibling MediaObjectTrait::style method reachable through the same Markdown excerpt-action pipeline, allowing an editor to save Markdown image style parameters that are written into the rendered img style attribute without sanitization. This issue is fixed in version 2.0.0-rc.9.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	getgrav/grav	2.0.0-rc.9	GHSA-pmf8-g7c8-7v54

Affected products (as reported)

Vendor	Product	Versions
getgrav	grav	< 2.0.0-rc.9

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

References

https://github.com/getgrav/grav/security/advisories/GHSA-pmf8-g7c8-7v54 x_refsource_CONFIRM
https://github.com/getgrav/grav/commit/24fd6cbc438e12310b126d1176e7d7601203a6f2 x_refsource_MISC
https://github.com/getgrav/grav/releases/tag/2.0.0-rc.9 x_refsource_MISC