# Gitlab authentication overwrites existing

**URL:** <https://forum.mattermost.com/t/gitlab-authentication-overwrites-existing/9902>\
**Category:** Troubleshooting\
**Created:** [June 4, 2020, 1:46pm UTC](https://forum.mattermost.com/t/gitlab-authentication-overwrites-existing/9902 "2020-06-04T13:46:50Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![axgwa](https://avatars.discourse-cdn.com/v4/letter/a/ecc23a/32.png) [@axgwa](https://forum.mattermost.com/u/axgwa)\
**Post date:** [June 4, 2020, 1:46pm UTC](https://forum.mattermost.com/t/gitlab-authentication-overwrites-existing/9902/1 "2020-06-04T13:46:50Z")

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We use GitLab as our authentication service. We realized that in some cases Gitlab has overwritten existing user while a new user joins mattermost. Is this a known bug?

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**Author:** ![amy.blais](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mattermost.com/amy.blais/32/7481_2.png) [@amy.blais](https://forum.mattermost.com/u/amy.blais)\
**Post date:** [June 4, 2020, 6:27pm UTC](https://forum.mattermost.com/t/gitlab-authentication-overwrites-existing/9902/2 "2020-06-04T18:27:45Z")

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What Mattermost version are you on?

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**Author:** ![axgwa](https://avatars.discourse-cdn.com/v4/letter/a/ecc23a/32.png) [@axgwa](https://forum.mattermost.com/u/axgwa)\
**Post date:** [June 4, 2020, 7:43pm UTC](https://forum.mattermost.com/t/gitlab-authentication-overwrites-existing/9902/3 "2020-06-04T19:43:14Z")

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We have the version 5.16.0

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<div class="post-metadata">

**Author:** ![amy.blais](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mattermost.com/amy.blais/32/7481_2.png) [@amy.blais](https://forum.mattermost.com/u/amy.blais)\
**Post date:** [June 4, 2020, 11:19pm UTC](https://forum.mattermost.com/t/gitlab-authentication-overwrites-existing/9902/4 "2020-06-04T23:19:54Z")

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Would you be open to upgrading to one of our supported versions? We support versions v5.19 and later.