{"cve":{"cve_id":"CVE-2021-41263","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.00608,"epss_percentile":0.44434,"epss_as_of":"2026-06-23","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.","published_at":"2021-11-15T20:10:11Z","last_modified_at":null,"cvss_v3_score":8.3,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H","cvss_v3_severity":"HIGH","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-200","CWE-565"],"nvd_references":["https://github.com/discourse/rails_multisite/security/advisories/GHSA-844m-cpr9-jcmh","https://github.com/discourse/rails_multisite/commit/c6785cdb5c9277dd2c5ac8d55180dd1ece440ed0"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-28T23:16:12.770802Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"L","value_label":"Low"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"L","value_label":"Low"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"discourse","vendor_name":"discourse","product_slug":"rails-multisite","product_name":"rails_multisite","version_start":"< 4.0.0","version_start_inclusive":true,"version_end":"< 4.0.0","version_end_inclusive":true,"cpe23_uri":"cve5:discourse:rails-multisite:< 4.0.0:< 4.0.0"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/discourse/rails_multisite/security/advisories/GHSA-844m-cpr9-jcmh","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://github.com/discourse/rails_multisite/commit/c6785cdb5c9277dd2c5ac8d55180dd1ece440ed0","source_type":"PATCH","tags":["patch"]}],"timeline":[{"type":"published","at":"2021-11-15T20:10:11Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:19:34.559284Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:19:34.559284Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:19:34.559284Z","label":"CVSS score revised","source":"cvelistv5"}]}