GHSA-4WJ4-79RR-PVFF

Vulnerability from github – Published: 2026-07-08 15:32 – Updated: 2026-09-16 22:14
Withdrawn 2026-09-16 VLAI
Summary
Duplicate Advisory: Grav: Stored CSS injection via Markdown image resize() bypasses prior media style sanitizers in Grav
Details

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-ffmg-hfvg-jhg9. This link is maintained to preserve external references.

Original 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'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.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "getgrav/grav"
      },
      "versions": [
        "2.0.0-rc.9"
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-16T22:14:36Z",
    "nvd_published_at": "2026-07-08T14:17:20Z",
    "severity": "MODERATE"
  },
  "details": "### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-ffmg-hfvg-jhg9. This link is maintained to preserve external references.\n\n### Original Description\nGrav 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\u0027s 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 \u003cimg style=...\u003e 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.",
  "id": "GHSA-4wj4-79rr-pvff",
  "modified": "2026-09-16T22:14:37Z",
  "published": "2026-07-08T15:32:01Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/getgrav/grav/security/advisories/GHSA-ffmg-hfvg-jhg9"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-58657"
    },
    {
      "type": "WEB",
      "url": "https://github.com/getgrav/grav/commit/6582166173bb8eb5869d96aea384e0e73777c94c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/getgrav/grav/commit/e03d29aa0d3ece16d73c1ffccfa78df8bf5f28b8"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/grav-stored-css-injection-via-markdown-image-resize-action"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Duplicate Advisory: Grav: Stored CSS injection via Markdown image resize() bypasses prior media style sanitizers in Grav",
  "withdrawn": "2026-09-16T22:14:36Z"
}



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