CVE-2026-58657

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 <img style=...> 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.

CVSS v3 4.8 MEDIUM

4.8^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.7 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required HIGH

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/getgrav/grav/commit/6582166173bb8eb5869d96aea384e0e73777c94c
https://github.com/getgrav/grav/commit/e03d29aa0d3ece16d73c1ffccfa78df8bf5f28b8
https://github.com/getgrav/grav/security/advisories/GHSA-ffmg-hfvg-jhg9
https://www.vulncheck.com/advisories/grav-stored-css-injection-via-markdown-image-resize-action
https://github.com/getgrav/grav/security/advisories/GHSA-ffmg-hfvg-jhg9

Configurations

No configuration.

History

08 Jul 2026, 15:16

Type	Values Removed	Values Added
References	~~() https://github.com/getgrav/grav/security/advisories/GHSA-ffmg-hfvg-jhg9 -~~	() https://github.com/getgrav/grav/security/advisories/GHSA-ffmg-hfvg-jhg9 -

08 Jul 2026, 14:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-08 14:17

Updated : 2026-07-08 15:28

NVD link : CVE-2026-58657

Mitre link : CVE-2026-58657

CVE.ORG link : CVE-2026-58657

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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