Clarify frame-ancestors behavior in nested frames#40886
Merged
Conversation
Added clarification on the behavior of the frame-ancestors directive in nested frames.
github-actions
bot
added
Content:HTTP
![github-actions[bot]](https://avatars.githubusercontent.com/in/15368?s=60&v=4){kind=small}
…/frame-ancestors/index.md Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Contributor
|
Preview URLs Flaws (3)URL:
External URLs (1)URL:
(comment last updated: 2025-08-26 08:53:51) |
bsmth
reviewed
Aug 26, 2025
…/frame-ancestors/index.md Co-authored-by: Brian Smith <brian@smith.berlin>
bsmth
approved these changes
Aug 26, 2025
Member
bsmth
left a comment
bsmth
left a comment
There was a problem hiding this comment.
Thanks a lot for the clarification! Welcome aboard!
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
3 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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Description
Added clarification on the behavior of the frame-ancestors directive in nested frames.
Motivation
While CSP 2 spec is clear about the frame-ancestor behavior when it comes to nested frames, MDN docs don't have any mention of it. This could lead to CSP errors in production if someone sets
frame-ancestordirective solely relying on MDN.Additional details
https://www.w3.org/TR/CSP2/#frame-ancestors-and-frame-options
Related issues and pull requests