CVE-2026-77560 — HIGH (8.1)

Vulnerability Description

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.

CVSS Score

8.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

NONE

Related Weaknesses (CWE)

CWE-636 CWE-178 CWE-863

References

FAQ

What is CVE-2026-77560?

CVE-2026-77560 is a vulnerability with a CVSS score of 8.1 (HIGH). 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, allo...

How severe is CVE-2026-77560?

CVE-2026-77560 has been rated HIGH with a CVSS base score of 8.1/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-77560?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.