Summary
Ghost: Member existence leak via magic link sign-in response
Advisory details
Impact
A discrepancy in responses from the members signin endpoints made it possible for an unauthenticated attacker to determine whether a given email address belongs to a registered member of a Ghost site.
Vulnerable versions
This vulnerability is present in Ghost from v5.18.0 up to v6.21.0.
Patches
v6.21.1 contains a fix for this issue.
How to update
For self-hosters using Docker, find Docker's official Ghost image here. Updating a Docker-based Ghost instance is documented here.
If your Ghost is a Ghost-CLI install see our documentation on updating it to the latest version here.
For more information
If you have any questions or comments about this advisory, email Ghost at security@ghost.org.
References
- https://github.com/advisories/GHSA-chgm-3698-jm42
- https://github.com/TryGhost/Ghost/security/advisories/GHSA-chgm-3698-jm42
- https://nvd.nist.gov/vuln/detail/CVE-2026-53947
- https://github.com/TryGhost/Ghost/pull/26752
- https://github.com/TryGhost/Ghost/commit/fb2bb634653d99de68fc42d415721d755284fe30
- https://github.com/TryGhost/Ghost/releases/tag/v6.21.1
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