{"cve":"CVE-2026-77560","nvd":{"published":"2026-09-21T17:18:52.770","modified":"2026-09-24T21:25:27.050","status":"Deferred","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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","score":8.1},"cwes":["CWE-178","CWE-636","CWE-863"],"references":["https://github.com/tinyauthapp/tinyauth/commit/80bc87188ec3aabc5104c249eaa7b997973b9275","https://github.com/tinyauthapp/tinyauth/commit/e75605b2c534ec83525a33603e16d76baca13399","https://github.com/tinyauthapp/tinyauth/pull/1000","https://github.com/tinyauthapp/tinyauth/pull/1028","https://github.com/tinyauthapp/tinyauth/releases/tag/v5.1.2"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:55:23.253742848+00:00"},"epss":{"cve":"CVE-2026-77560","score":0.00612,"percentile":0.49339,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-328g-jx67-v94g","url":"https://osv.dev/vulnerability/GHSA-328g-jx67-v94g","summary":"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","modified":"2026-10-01T20:56:18.875153850Z","packages":[{"ecosystem":"Go","name":"github.com/tinyauthapp/tinyauth","purl":"pkg:golang/github.com/tinyauthapp/tinyauth","ranges":["<1.0.1-0.20260720133915-80bc87188ec3"],"fixed":["1.0.1-0.20260720133915-80bc87188ec3"]}]},{"id":"GO-2026-6552","url":"https://osv.dev/vulnerability/GO-2026-6552","summary":"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 in github.com/tinyauthapp/tinyauth","modified":"2026-10-01T20:45:13.176846719Z","packages":[{"ecosystem":"Go","name":"github.com/tinyauthapp/tinyauth","purl":"pkg:golang/github.com/tinyauthapp/tinyauth","ranges":["<1.0.1-0.20260720133915-80bc87188ec3"],"fixed":["1.0.1-0.20260720133915-80bc87188ec3"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}