CVE-2026-77560

8.1 HIGHpublic exploit available

Published 2026-09-21 · Updated 2026-09-21

AI risk analysis

Summary: The flaw allows an authenticated low-privilege user to bypass per-app access controls by using a differently cased hostname, potentially gaining unauthorized access. This matters because it undermines security measures designed to restrict access based on case-insensitive hostnames.
Exploitability: Exploitation requires control over the forwarded hostname and authentication as a low-privilege user. The attacker must use a different casing of an existing hostname to bypass per-app restrictions.
Blast radius: If exploited, this could lead to unauthorized access to applications with strict access controls, compromising sensitive data or functionality.
Prioritized remediation: Update to Tinyauth version 5.1.2 or later to address the vulnerability.

auth-bypasswebmisconfigurationcase-sensitivity

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD 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 vector

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

Weaknesses

CWE-178, CWE-636, CWE-863

Public exploit & PoC references

All references

Source data: NVD (nvd.nist.gov), public domain. Exploit-DB.ai adds local AI analysis for defensive use only.

Related CVEs

Related by shared AI tags and CWE weakness class. Browse the full archive.