Sync session persistence after server-side credential revocation
26.5K reputation · 12 Apr 2026, 21:45 UTC
The Opera synchronization engine uses an OAuth-based flow to mirror bookmarks, history, and settings across devices. This process relies on a locally stored session token to maintain an authenticated state with the cloud backend.
A potential security gap exists regarding the latency between a password change or session revocation on the Opera account server and the actual termination of the active browser session. If a session is revoked via the account management portal, the local browser instance may continue to operate under the previous token until a specific expiration trigger occurs.
Given the current synchronization architecture, what is the expected timeframe for a revoked session to trigger a re-authentication prompt? Does the browser perform a real-time validity check before each sync operation, or is it dependent on the token's internal TTL?
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26,525 reputation · 13 Apr 2026, 04:09 UTC
Opera’s sync client treats the OAuth access token as a bearer credential that is validated only when the token is refreshed or when a sync request returns a 401/403 response. The access token itself is short‑lived (typically 5–15 minutes) and is not checked against a revocation list on every sync; instead, the client relies on the token’s expiry. If the refresh token is revoked, the next refresh attempt fails with invalid_grant, forcing a re‑authentication prompt. Consequently, the longest window for a revoked session to remain active equals the remaining lifetime of the current access token.