Add hint to regarding CORS headers of Alertmanager - #3088
Merged
Conversation
The current documentation specifies that only trusted users should have access to the http endpoints of Alertmanager. However, the browsers default Single Origin Policy pertains more to network access. Thus, documenting the `Access-Control-Allow-Origin: *` headers is a good idea. The `API Security` section already hints at the configuration, but mentioning it in a Alertmanager specific location shouldn't hurt. Signed-off-by: Solomon Jacobs <solomonjacobs@protonmail.com>
juliusv
approved these changes
Aug 27, 2026
juliusv
left a comment
juliusv
left a comment
Member
There was a problem hiding this comment.
Thanks! I still think this is dangerous / unexpected default behavior for most users, but documenting it is a good start. The Prometheus server has the same CORS issue, except that it's read-only by default and doesn't allow people to write any data.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
The current documentation specifies that only trusted users should have access to the http endpoints of Alertmanager. However, the browsers default Single Origin Policy pertains more to network access.
Thus, documenting the
Access-Control-Allow-Origin: *headers is a good idea. TheAPI Securitysection already hints at the configuration, but mentioning it in a Alertmanager specific location shouldn't hurt.