CVE-2026-77560: Tinyauth is an authentication and authorization server. Prior to 5.1.2, Tinyauth compares forwarded hostnames case-sensitively while reverse proxies route…

PriorityP357high8.1CVSS 3.1

AVNACLPRLUINSUCHIHAN

EPSS

0.61%

49.0th percentile

Tinyauth is an authentication and authorization server. Prior to 5.1.2, Tinyauth compares forwarded hostnames case-sensitively while reverse proxies route equivalent hostnames case-insensitively, allowing an authenticated low-privilege user to bypass per-app access controls with a differently cased hostname. The lookup in internal/service/access_controls_service.go through lookupStaticACLs and GetAccessControls, and the Docker-label fallback in internal/service/docker_service.go through GetLabels, can miss the configured app and return an empty access-control object. internal/controller/proxy_controller.go proxyHandler then treats the empty user, group, OAuth, LDAP, and IP restrictions as permissive and returns an authenticated result for an app that should exclude the user. Unauthenticated users remain subject to login, and global login-time allowlists are not bypassed. This issue is fixed in version 5.1.2.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
github.com	tinyauthapp_tinyauth	>= 0 < 1.0.1-0.20260720133915-80bc87188ec3	1.0.1-0.20260720133915-80bc87188ec3
tinyauthapp	tinyauth	< 5.1.2	5.1.2

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