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CVE-2026-58657

CVE-2026-58657 · Grav - Stored CSS Injection via Markdown Image resize() Action

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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 4.8 · Medium · EPSS 0.3% · Fix available

Published
Updated

Stack: php

Affected products and versions

  • grav

    Versions
    • ≥ 2.0.0-rc.9, < 2.0.0: Affected (semver)
    • 2.0.0: Not affected (semver)

    Update to 2.0.0

  • getgrav/grav Packagist

    Versions
    • 2.0.0-rc.10
    • 2.0.0-rc.9
    Affected ranges
    • ECOSYSTEM: ≥ 2.0.0-rc.9, < 2.0.0

    Update to 2.0.0

Original sources

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