{"cve":"CVE-2021-41263","nvd":{"published":"2021-11-15T20:15:20.037","modified":"2026-06-17T04:08:11.787","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-327","CWE-200","CWE-565"],"references":["https://github.com/discourse/rails_multisite/commit/c6785cdb5c9277dd2c5ac8d55180dd1ece440ed0","https://github.com/discourse/rails_multisite/security/advisories/GHSA-844m-cpr9-jcmh","https://github.com/discourse/rails_multisite/commit/c6785cdb5c9277dd2c5ac8d55180dd1ece440ed0","https://github.com/discourse/rails_multisite/security/advisories/GHSA-844m-cpr9-jcmh"],"products":["discourse:rails_multisite"],"source":"nvd","synced_at":"2026-10-19T21:25:41.256909649+00:00"},"epss":{"cve":"CVE-2021-41263","score":0.00628,"percentile":0.50116,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-844m-cpr9-jcmh","url":"https://osv.dev/vulnerability/GHSA-844m-cpr9-jcmh","summary":"Rails Multisite secure/signed cookies share secrets between sites in a multi-site application","modified":"2026-07-08T06:28:21.002220346Z","packages":[{"ecosystem":"RubyGems","name":"rails_multisite","purl":"pkg:gem/rails_multisite","ranges":["<4.0.0"],"fixed":["4.0.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}