Answer in brief
CVE-2026-77560 records a Unknown severity vulnerability in Tinyauth: forward-auth per-app ACL is matched case-sensitively against the (case-insensitive) hostname, letting an authenticated user reach apps they are not on the allowlist for. The current sources do not mark it as known exploited. The current feed maps tinyauthapp/tinyauth (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps tinyauthapp/tinyauth (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| tinyauthapp/tinyauthgeneric | < 5.1.2 | Not reported |
Published upstream
Sep 21, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 21, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 21, 2026
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.
Quoted source text, attributed separately from HOL analysis.