Bitbucket Pipelines Failing Due to Authentication Error — Need Help Identifying the Cause

[Alex Dane]

Hi everyone,

I’m facing an authentication issue in Bitbucket Pipelines and can’t seem to identify what’s causing it. My pipeline was working fine earlier, but recently it started failing with an authentication-related error during runtime.

I’ve already checked the following:

Repository variables and secrets are correctly set

App passwords and tokens are active

No recent changes were made in the pipeline YAML

Local authentication works without any issues

Despite this, Pipelines keeps failing whenever it tries to authenticate with the external service.

Has anyone experienced this before or knows what might cause Pipelines to suddenly reject valid credentials? Any guidance or troubleshooting steps would be really appreciated.

Thanks in advance!

[Faisu khan · Accepted solution]

This issue usually happens when Pipelines is using an outdated or invalid credential even if the variables look correct. Bitbucket caches environment variables per build image, so the first thing to try is:

1. Re-save all repository variables
Edit → Save (even without changes). This forces Pipelines to refresh them.

2. Check if your app password/token has new required scopes
Some services update their permission scopes, and Pipelines fails while local still works.

3. Verify that the credential is not being overwritten in the YAML
Check for duplicate variables or step-level overrides.

4. Regenerate the app password/token
Most authentication errors resolve immediately after generating a new key.

If none of these help, share the exact error log so we can pinpoint whether it’s a service-side rejection or Pipelines environment issue.