CVE-2026-58657

Severity CVSS v4.0:

MEDIUM

Type:

CWE-79 Cross-Site Scripting (XSS)

Publication date:

08/07/2026

Last modified:

08/07/2026

Description

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&#39;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.

Impact

Vector 4.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 4.80 MEDIUM
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): High
User Interaction (UI): Passsive
Confidentiality (VC): Low
Integrity (VI): Low
Availability (VA): None
Confidentiality (SC): Low
Integrity (SI): Low
Availability (SA): None

Base Score 4.0

4.80

Severity 4.0

MEDIUM

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N CVSS v3.1 Severity and Metrics:

Base Score: 4.80 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): High
User Interaction (UI): Required
Scope (S): Changed
Confidentiality (C): Low
Integrity (I): Low
Availability (A): None

Base Score 3.x

4.80

Severity 3.x

MEDIUM

CVE-2026-58657

Description

Impact

References to Advisories, Solutions, and Tools