{"id":"EUVD-2026-18254","revision":"99d63bb109d847a4bb8c8aa2526270f0","records":[{"revision":"99d63bb109d847a4bb8c8aa2526270f0","observedAt":"2026-10-28T04:00:31.238+00:00","statement":{"source":"euvd","id":"EUVD-2026-18254","aliases":["CVE-2026-33544","GHSA-9q5m-jfc4-wc92"],"title":"Tinyauth is an authentication and authorization server. Prior to version 5.0.5, all three OAuth service implementations (GenericOAuthService, GithubOAuthService, GoogleOAuthService) store PKCE verifiers and access tokens as mutable struct f…","description":"Tinyauth is an authentication and authorization server. Prior to version 5.0.5, all three OAuth service implementations (GenericOAuthService, GithubOAuthService, GoogleOAuthService) store PKCE verifiers and access tokens as mutable struct fields on singleton instances shared across all concurrent requests. When two users initiate OAuth login for the same provider concurrently, a race condition between VerifyCode() and Userinfo() causes one user to receive a session with the other user's identity. This issue has been patched in version 5.0.5.","state":0,"publishedAt":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N","score":7.7,"severity":null}],"references":["https://github.com/steveiliop56/tinyauth/security/advisories/GHSA-9q5m-jfc4-wc92","https://github.com/steveiliop56/tinyauth/commit/f26c2171610d5c2dfbba2edb6ccd39490e349803","https://github.com/steveiliop56/tinyauth/releases/tag/v5.0.5"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-18254","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"Apr 2, 2026, 3:00:38 PM","dateUpdated":"Apr 3, 2026, 6:23:22 PM"},"relatedAdvisories":[],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2026-18254","identifiers":["EUVD-2026-18254","CVE-2026-33544","GHSA-9q5m-jfc4-wc92"]},"retained":false,"historicalAffected":[]}],"coverage":[]}