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AWS · Cloud and hostingSep 3, 2026, 21:49 UTC

Increased API Error Rates

MinorNot disclosedUpdated 19h ago
Sep 3, 21:49 UTCSep 4, 00:07 UTC
Duration
2h 18m
Impact
Minor
Root cause
Not disclosed
AWS, 90 days
12 incidents
Affected
Multiple servicesus-west-2
Status page

Final update

Between 2:12 PM and 3:18 PM PDT, we experienced increased API error rates affecting the STS AssumeRoleWithSAML and AssumeRoleWithWebIdentity APIs in the US-WEST-2 Region. The root cause was determined to be due to an issue with an STS subsystem responsible for communicating with external identity providers. Other AWS Services that rely on these identity federation protocols were also affected. At 3:18 PM, we observed signs of recovery and continued to monitor to ensure stability and full recovery. The issue is resolved and the service is operating normally at this time.

Timeline

  1. Resolved · Sep 4, 00:07 UTC
    Between 2:12 PM and 3:18 PM PDT, we experienced increased API error rates affecting the STS AssumeRoleWithSAML and AssumeRoleWithWebIdentity APIs in the US-WEST-2 Region. The root cause was determined to be due to an issue with an STS subsystem responsible for communicating with external identity providers. Other AWS Services that rely on these identity federation protocols were also affected. At 3:18 PM, we observed signs of recovery and continued to monitor to ensure stability and full recovery. The issue is resolved and the service is operating normally at this time.
  2. Update · Sep 3, 23:20 UTC
    We continue to see recovery holding steady for the STS AssumeRoleWithSAML and AssumeRoleWithWebIdentity APIs in the US-WEST-2 Region. Error rates are now back to pre-event levels, and we continue actively monitoring to confirm full recovery. We will provide another update by 5:15 PM or earlier.
  3. Update · Sep 3, 22:26 UTC
    We are seeing early signs of recovery and continue to monitor for full recovery. We will provide another update at 4:15 PM, or sooner if we have additional information to share.
  4. Update · Sep 3, 21:49 UTC
    Starting at 2:12 PM PDT, we began experiencing increased API error rates for STS and Sign In when using SAML in the US-WEST-2 Region. Our engineering team was automatically engaged at 2:19 PM to begin investigating the root cause. There is no work around available at this time. We will provide another update by 3:30 PM PDT.

More from AWS

Full history
StartedIncidentDuration
Sep 2123:26 UTCIncreased Error Rates58m
Aug 2102:02 UTCIncreased Error Rates38m
Aug 1915:15 UTCIncreased Error Rates3h 32m
Aug 1503:42 UTCIncreased Packet loss3d
Jul 3117:33 UTCElevated Packet Loss1h 21m
Jul 2411:40 UTCConnectivity Issues1h 21m

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