Grav Admin (getgrav/grav-plugin-admin2) versions <= 2.0.19 contain a stored cross-site scripting vulnerability in the tHtml() function (src/lib/stores/i18n.svelte.ts), which substitutes untrusted parameters such as usernames into translation templates before parsing the result as markdown. Grav's server-side username validation (DataUser::isValidUsername) blocks filesystem-dangerous characters but not <, >, ", or ', allowing an attacker to register a username containing an HTML payload. When an administrator views a UI surface that renders the username through tHtml()—such as the two-factor force-disable confirmation prompt or the 'page is locked' editor notice—the payload executes in their authenticated session. Fixed in 2.0.21.
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Fixes
Solution
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Workaround
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References
History
Fri, 04 Sep 2026 11:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Grav Admin (getgrav/grav-plugin-admin2) versions <= 2.0.19 contain a stored cross-site scripting vulnerability in the tHtml() function (src/lib/stores/i18n.svelte.ts), which substitutes untrusted parameters such as usernames into translation templates before parsing the result as markdown. Grav's server-side username validation (DataUser::isValidUsername) blocks filesystem-dangerous characters but not <, >, ", or ', allowing an attacker to register a username containing an HTML payload. When an administrator views a UI surface that renders the username through tHtml()—such as the two-factor force-disable confirmation prompt or the 'page is locked' editor notice—the payload executes in their authenticated session. Fixed in 2.0.21. | |
| Title | Grav Admin before 2.0.21 Stored XSS via username | |
| First Time appeared |
Getgrav
Getgrav grav |
|
| Weaknesses | CWE-79 | |
| CPEs | cpe:2.3:a:getgrav:grav:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Getgrav
Getgrav grav |
|
| References |
| |
| Metrics |
cvssV3_1
|
Projects
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Status: PUBLISHED
Assigner: VulnCheck
Published:
Updated: 2026-09-04T11:30:02.813Z
Reserved: 2026-09-04T11:00:28.731Z
Link: CVE-2026-85600
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OpenCVE Enrichment
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Weaknesses