{"id":"GHSA-844m-cpr9-jcmh","summary":"Rails Multisite secure/signed cookies share secrets between sites in a multi-site application","details":"### Impact\nThis vulnerability impacts any Rails applications using `rails_multisite` alongside Rails' signed/encrypted cookies. Depending on how the application makes use of these cookies, it may be possible for an attacker to re-use cookies on different 'sites' within a multi-site Rails application.\n\n### Patches\nThe issue has been patched in v4 of the `rails_multisite` gem. Note that this upgrade will invalidate all previous signed/encrypted cookies. The impact of this invalidation will vary based on the application architecture.","aliases":["CVE-2021-41263"],"modified":"2026-07-08T06:28:21.002220346Z","published":"2021-11-15T17:54:01Z","database_specific":{"github_reviewed_at":"2021-11-15T17:53:35Z","nvd_published_at":"2021-11-15T20:15:00Z","cwe_ids":["CWE-200","CWE-327","CWE-565"],"severity":"MODERATE","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/discourse/rails_multisite/security/advisories/GHSA-844m-cpr9-jcmh"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-41263"},{"type":"WEB","url":"https://github.com/discourse/rails_multisite/commit/c6785cdb5c9277dd2c5ac8d55180dd1ece440ed0"},{"type":"PACKAGE","url":"https://github.com/discourse/rails_multisite"},{"type":"WEB","url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rails_multisite/CVE-2021-41263.yml"}],"affected":[{"package":{"name":"rails_multisite","ecosystem":"RubyGems","purl":"pkg:gem/rails_multisite"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.0"}]}],"versions":["0.0.1","1.0.1","1.0.2","1.0.3","1.0.4","1.0.5","1.0.6","1.1.0","1.1.0.rc1","1.1.0.rc2","1.1.0.rc3","1.1.0.rc4","1.1.1","1.1.2","2.0.1","2.0.2","2.0.4","2.0.6","2.0.7","2.1.0","2.1.1","2.1.2","2.2.2","2.3.0","2.4.0","2.5.0","3.0.0","3.1.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/11/GHSA-844m-cpr9-jcmh/GHSA-844m-cpr9-jcmh.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:L/A:H"}]}