CVE-2026-67333: medium-severity vulnerability in better-auth
better-auth before 1.6.13 Stored XSS via javascript redirect_uri
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.1epss 0.3%
better-auth before 1.6.13 (and pre-release builds 1.7.0-beta.0 through 1.7.0-beta.3) fail to validate the scheme of redirect_uris registered via the deprecated oidc-provider plugin and the mcp plugin (which wraps the same provider). An attacker can register an OAuth client with a javascript: redirect_uri, which the authorization server later returns unchanged in the consent response. If the deployment's consent page navigates the browser to the returned redirectURI (e.g. assigning it to window.location.href), the attacker's JavaScript executes in the authorization-server origin, exposing the victim's session and enabling account takeover.
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
Affected products
better-auth · better-authRelated CVEs — better-auth
In the same product, most dangerous first.
CVE-2025-61928CRITICALBetter Auth: Unauthenticated API key creation through api-key pluginEPSS 19.7%CVE-2025-71404MEDIUMbetter-auth before 1.1.16 Reflected XSS via error parameterEPSS 0.7%CVE-2025-71399HIGHBetter Auth before 1.4.5 Path Normalization Bypass via rou3EPSS 0.5%CVE-2026-67337HIGHbetter-auth before 1.4.9 Two-Factor Authentication Bypass via session.cookieCacheEPSS 0.5%CVE-2025-71401CRITICALbetter-auth before 1.4.2 basePath Modification DoSEPSS 0.5%CVE-2026-67327HIGHbetter-auth before 1.6.22 Account Takeover via Magic-Link Email-OTPEPSS 0.4%