{"id":"GHSA-4wj4-79rr-pvff","title":"Duplicate Advisory: Grav: Stored CSS injection via Markdown image resize() bypasses prior media style sanitizers in Grav","summary":"Duplicate Advisory: Grav: Stored CSS injection via Markdown image resize() bypasses prior media style sanitizers in Grav","severity":"medium","cvss":4.8,"cwe":["CWE-79"],"vendor":"getgrav","product":"getgrav/grav","ecosystem":"composer","affected":["getgrav/grav = 2.0.0-rc.9"],"published":"2026-07-08","updated":"2026-09-16","sourceUpdated":"2026-09-16T22:14:38Z","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-4wj4-79rr-pvff","references":[{"url":"https://github.com/getgrav/grav/security/advisories/GHSA-ffmg-hfvg-jhg9"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-58657"},{"url":"https://github.com/getgrav/grav/commit/6582166173bb8eb5869d96aea384e0e73777c94c"},{"url":"https://github.com/getgrav/grav/commit/e03d29aa0d3ece16d73c1ffccfa78df8bf5f28b8"},{"url":"https://www.vulncheck.com/advisories/grav-stored-css-injection-via-markdown-image-resize-action"},{"url":"https://github.com/advisories/GHSA-4wj4-79rr-pvff"}],"tags":["ghsa","composer"],"ingestedAt":"2026-09-16T23:07:58.094Z","slug":"GHSA-4wj4-79rr-pvff","body":"## Overview\n\n### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-ffmg-hfvg-jhg9.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'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.\n\n## Affected packages\n\n- `getgrav/grav = 2.0.0-rc.9`\n\n## Remediation\n\nRefer to the advisory for the patched release.","depth":"sunlit","depthScore":26,"depthScoreParts":{"impact":26.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}