MEDIUM 5.3 GitHub
CVE-2026-53947
Ghost: Member existence leak via magic link sign-in response
### 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](https://hub.docker.com/_/ghost). Updating a Dock
Affected Products
- npm/ghost >= 5.18.0, < 6.21.1
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
This medium severity vulnerability with a CVSS score of 5.3 was published on 2026-08-04 via GitHub. Affected: npm/ghost >= 5.18.0, < 6.21.1.
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