CVE-2026-85600
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Summary
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.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| getgrav | grav | 0 < 2.0.21 | affected |
| getgrav | grav | 2.0.21 | unaffected |
Weaknesses
- CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: poc
- Automatable: no
- Technical Impact: partial
Additional References
References
- https://github.com/getgrav/grav/security/advisories/GHSA-96xm-c5hr-59rx
- https://www.vulncheck.com/advisories/grav-admin-before-2.0.21-stored-xss-via-username
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