Admin-session code execution via unsanitized Markdown HTML
Published Sep 4, 2026 · Updated Sep 4, 2026
Stored cross-site scripting in Grav Admin before 2.0.20 allows remote attackers to execute code in authenticated admin sessions. MarkdownEditor and MarkdownModal pass marked.parse() output directly to Svelte's {@html} directive, leaving javascript: link schemes unsanitized. Exploitation requires an administrator to open a crafted plugin or theme changelog and activate its link, enabling actions in that admin context.
Summary
What happened
Stored cross-site scripting in Grav Admin before 2.0.20 allows remote attackers to execute code in authenticated admin sessions. MarkdownEditor and MarkdownModal pass marked.parse() output directly to Svelte's {@html} directive, leaving javascript: link schemes unsanitized. Exploitation requires an administrator to open a crafted plugin or theme changelog and activate its link, enabling actions in that admin context.
The record
- CVE
- CVE-2026-85601
- Published
- Sep 4, 2026
- Updated
- Sep 4, 2026
- Vendor
- Grav
- Product
- Grav
- Classifications
- CWE-79, T1204.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 4, 2026CVE publishedPublication date reported by the CVE source.
- Sep 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <2.0.20
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- marked.js javascript URI proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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