Impact An attacker was able to craft a malicious link that, when accessed by an authenticated staff user or member, would execute JavaScript with the victim's permissions, potentially leading to account takeover.

Vulnerable versions This vulnerability is present in Ghost versions: - v5.43.0 to v5.120.4 - v6.0.0 to v6.14.0

As well as in Portal versions: - v2.29.1 to v2.51.4 - v2.52.0 to v2.57.0

Patches Ghost automatically loads the latest patch of the members Portal component via CDN. Therefore: - For Ghost 5.x users, upgrading to v5.121.0 or later fixes the vulnerability (loads Portal v2.51.5, which contains the patch) - For Ghost 6.x users, upgrading to v6.15.0 or later fixes the vulnerability (loads Portal v2.57.1, which contains the patch)

For Ghost installations using a customised or self-hosted version of Portal, it will be necessary to manually rebuild from or update to the latest patch version.

References Ghost thanks Younes Belalia for discovering and disclosing this vulnerability responsibly.

For more information If users have any questions or comments about this advisory, email Ghost at security@ghost.org.