{"record":{"id":"ac7abf7f7b25d9fe","repo":"oauth2-proxy/oauth2-proxy","slug":"error-decoding-ticket-to-clear-session-v","errorCode":null,"errorMessage":"error decoding ticket to clear session: %v","messagePattern":"error decoding ticket to clear session: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/sessions/persistence/manager.go","lineNumber":86,"sourceCode":"\t)\n}\n\n// Clear clears any saved session information for a given ticket cookie.\n// Then it clears all session data for that ticket in the Store.\nfunc (m *Manager) Clear(rw http.ResponseWriter, req *http.Request) error {\n\ttckt, err := decodeTicketFromRequest(req, m.Options)\n\tif err != nil {\n\t\t// Always clear the cookie, even when we can't load a cookie from\n\t\t// the request\n\t\ttckt = &ticket{\n\t\t\toptions: m.Options,\n\t\t}\n\t\ttckt.clearCookie(rw, req)\n\t\t// Don't raise an error if we didn't have a Cookie\n\t\tif err == http.ErrNoCookie {\n\t\t\treturn nil\n\t\t}\n\t\treturn fmt.Errorf(\"error decoding ticket to clear session: %v\", err)\n\t}\n\n\ttckt.clearCookie(rw, req)\n\treturn tckt.clearSession(func(key string) error {\n\t\treturn m.Store.Clear(req.Context(), key)\n\t})\n}\n\n// VerifyConnection validates the underlying store is ready and connected\nfunc (m *Manager) VerifyConnection(ctx context.Context) error {\n\treturn m.Store.VerifyConnection(ctx)\n}\n","sourceCodeStart":68,"sourceCodeEnd":99,"githubUrl":"https://github.com/oauth2-proxy/oauth2-proxy/blob/33c2eb92dea78204f7a18bc2dfdbccc220f39257/pkg/sessions/persistence/manager.go#L68-L99","documentation":"Manager.Clear decodes the ticket from the request cookie before clearing session state server-side. If decoding fails with any error other than http.ErrNoCookie (e.g. malformed ticket string), Clear returns this wrapped error because it cannot derive the store key to delete.","triggerScenarios":"Calling Clear on a request whose cookie holds a malformed ticket (wrong number of dot-separated parts, invalid base64 ID/secret) rather than simply missing a cookie.","commonSituations":"Client cookies corrupted or hand-edited; ticket format changed between library versions (v2 encoding vs old format) leaving stale cookies; proxy mangling cookie values.","solutions":["Have the user clear their cookies; the server session becomes orphaned but the client recovers.","Treat malformed tickets like missing ones: check for http.ErrNoCookie and log/swallow other decode errors when a best-effort clear is acceptable.","Roll out ticket-format changes with a grace period or version check so old cookies are cleared gracefully.","Verify no proxy/CDN is truncating or rewriting the Cookie header."],"exampleFix":"// before\nif err == http.ErrNoCookie {\n    return nil\n}\nreturn fmt.Errorf(\"error decoding ticket to clear session: %v\", err)\n// after\nif errors.Is(err, http.ErrNoCookie) {\n    return nil\n}\n// malformed ticket: cookie will be cleared anyway; log and continue\nlog.Printf(\"clearing session with undecodable ticket: %v\", err)\ntckt.clearCookie(rw, req)\nreturn nil","handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":"err := m.Clear(rw, req)\nif err != nil && !errors.Is(err, http.ErrNoCookie) {\n    // malformed ticket: cookie was already cleared; log and continue\n    log.Printf(\"session clear with bad ticket ignored: %v\", err)\n    err = nil\n}","preventionTips":["Treat undecodable tickets as 'no session' in Clear paths.","Use errors.Is(err, http.ErrNoCookie) rather than == for error matching.","Stage ticket-format migrations and clear old-format cookies gracefully."],"tags":["go","session","cookies","ticket"],"backgroundTag":"invalid-argument-format","analyzedSha":"33c2eb92dea78204f7a18bc2dfdbccc220f39257","analyzedAt":"2026-09-06T08:51:53.077Z","contentChangedAt":"2026-09-06T08:51:53.077Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}