Lychee is a free, open-source photo-management tool. Prior to 7.6.3, GET /api/v2/Zip authorizes album and photo archives through AlbumPolicy::canDownload() and PhotoPolicy::canDownload() without first enforcing AlbumPolicy::canAccess(). For a public, password-protected album with grants_download enabled, an unauthenticated attacker who knows the shared album identifier can download a ZIP archive without supplying the password or unlocking the album, even though browsing endpoints deny access. The archive exposes the album's photos and can include full-resolution originals and associated metadata when grants_full_photo_access is enabled. This issue is fixed in version 7.6.3.