{"id":"CVE-2021-41263","aliases":["EUVD-2021-2317","GHSA-844m-cpr9-jcmh"],"status":"published","title":"Secure/signed cookies share secrets between sites in rails_multisite","description":"rails_multisite provides multi-db support for Rails applications. In affected versions this 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. The 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.","severity":{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00628,"percentile":0.50392,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-200","CWE-327","CWE-565"],"published":"2021-11-15T17:54:01Z","modified":"2026-10-20T10:54:58Z","fixes":[{"ecosystem":"RubyGems","package":"rails_multisite","fixed_in":["4.0.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"RubyGems","package":"rails_multisite","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.0"}]}]},{"source":"osv","ecosystem":"RubyGems","package":"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"]}],"products":[{"vendor":"discourse","product":"rails_multisite"}],"references":[{"url":"https://github.com/discourse/rails_multisite/security/advisories/GHSA-844m-cpr9-jcmh","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/discourse/rails_multisite/commit/c6785cdb5c9277dd2c5ac8d55180dd1ece440ed0","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-41263","tags":["advisory"]},{"url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rails_multisite/CVE-2021-41263.yml","tags":["web"]},{"url":"https://github.com/advisories/GHSA-844m-cpr9-jcmh"},{"url":"https://github.com/discourse/rails_multisite","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2021-41263","title":"Secure/signed cookies share secrets between sites in rails_multisite","description":"rails_multisite provides multi-db support for Rails applications. In affected versions this 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. The 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.","status":"published","published":"2021-11-15T20:10:11Z","modified":"2024-08-04T03:08:31.596Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-200","CWE-565"],"updated_at":"2026-11-02T14:32:59.105382Z"}],"euvd":[{"id":"EUVD-2021-2317","description":"rails_multisite provides multi-db support for Rails applications. In affected versions this 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. The 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.","status":"published","published":"2021-11-15T20:10:11Z","modified":"2024-08-04T03:08:31Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H","level":"high"}],"updated_at":"2026-11-03T03:24:18.226903Z"}],"ghsa":[{"id":"GHSA-844m-cpr9-jcmh","title":"Rails Multisite secure/signed cookies share secrets between sites in a multi-site application","description":"### 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.","status":"published","published":"2021-11-15T17:54:01Z","modified":"2023-05-04T19:51:19Z","cvss":[{"version":"3.1","score":6.2,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:L/A:H","level":"medium"}],"cwes":["CWE-200","CWE-327","CWE-565"],"updated_at":"2026-11-02T14:36:52.310293Z"}],"nvd":[{"id":"CVE-2021-41263","description":"rails_multisite provides multi-db support for Rails applications. In affected versions this 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. The 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.","status":"published","published":"2021-11-15T20:15:20.037Z","modified":"2026-06-17T04:08:11.787Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":6,"vector":"AV:N/AC:M/Au:S/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-200","CWE-565","CWE-327"],"updated_at":"2026-11-02T14:07:00.984108Z"}],"osv":[{"id":"CVE-2021-41263","description":"rails_multisite provides multi-db support for Rails applications. In affected versions this 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. The 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.","status":"published","published":"2021-11-15T20:15:20.037Z","modified":"2026-10-20T10:54:58.570908382Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:21.557945Z"},{"id":"GHSA-844m-cpr9-jcmh","title":"Rails Multisite secure/signed cookies share secrets between sites in a multi-site application","description":"### 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.","status":"published","published":"2021-11-15T17:54:01Z","modified":"2026-07-08T06:28:21.002220346Z","cvss":[{"version":"3.1","score":6.2,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:L/A:H","level":"medium"}],"cwes":["CWE-200","CWE-327","CWE-565"],"updated_at":"2026-11-02T15:46:41.732368Z"}]}}