Shelf.io incident
Investigating: SSO login failures across regions
Shelf.io experienced a critical incident on September 10, 2025 affecting Authentication and Authentication and 1 more component, lasting 1h 57m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- investigating Sep 10, 2025, 04:06 PM UTC
Starting at 14:38 UTC, we observed a spike in SSO authentication failures. Affected users may be unable to sign in and see "access_denied (Unauthorized)" after returning from their IdP. We are actively investigating with our identity provider. Next update within 30 minutes.
- identified Sep 10, 2025, 04:26 PM UTC
We have deployed a fix to our authentication flow at 16:15 UTC. Users should begin to see successful sign-ins resume across all regions. Please retry logging in; starting a new browser session (or incognito) may help clear a failed attempt. We’re closely monitoring error rates and will provide another update within 30 minutes.
- resolved Sep 10, 2025, 04:35 PM UTC
SSO sign-ins have been restored. Between 14:38-16:27 UTC a configuration regression in our authentication layer caused the authorization code exchange to fail, resulting in "access_denied (Unauthorized)" after IdP login. We corrected the configuration and refreshed services; metrics show recovery across all regions.