{"id":"CVE-2021-36126","aliases":["BIT-mediawiki-2021-36126","EUVD-2021-22758","GHSA-pm9m-mcr8-3v4h"],"status":"published","title":"An issue was discovered in the AbuseFilter extension in MediaWiki through 1.36. If the MediaWiki...","description":"An issue was discovered in the AbuseFilter extension in MediaWiki through 1.36. If the MediaWiki:Abusefilter-blocker message is invalid within the content language, the filter user falls back to the English version, but that English version could also be invalid on a wiki. This would result in a fatal error, and potentially fail to block or restrict a potentially nefarious user.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.01201,"percentile":0.68466,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"published":"2021-07-02T13:01:05Z","modified":"2026-10-24T10:30:33Z","fixes":[{"ecosystem":"Bitnami","package":"mediawiki","fixed_in":["1.36.1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Bitnami","package":"mediawiki","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.36.1"}]}]}],"products":[{"vendor":"mediawiki","product":"mediawiki"}],"references":[{"url":"https://phabricator.wikimedia.org/T284364","tags":["x_refsource_MISC","x_transferred","Exploit","Issue Tracking","Patch","Vendor Advisory","web","fix"]},{"url":"https://gerrit.wikimedia.org/r/q/I9e9f44b7663e810de70fb9ac7f6760f83dd4895b","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory","web","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-36126","tags":["web"]},{"url":"https://github.com/advisories/GHSA-pm9m-mcr8-3v4h"}],"sources":{"cve":[{"id":"CVE-2021-36126","description":"An issue was discovered in the AbuseFilter extension in MediaWiki through 1.36. If the MediaWiki:Abusefilter-blocker message is invalid within the content language, the filter user falls back to the English version, but that English version could also be invalid on a wiki. This would result in a fatal error, and potentially fail to block or restrict a potentially nefarious user.","status":"published","published":"2021-07-02T13:01:05Z","modified":"2024-08-04T00:47:43.82Z","updated_at":"2026-11-02T14:33:06.32268Z"}],"euvd":[{"id":"EUVD-2021-22758","description":"An issue was discovered in the AbuseFilter extension in MediaWiki through 1.36. If the MediaWiki:Abusefilter-blocker message is invalid within the content language, the filter user falls back to the English version, but that English version could also be invalid on a wiki. This would result in a fatal error, and potentially fail to block or restrict a potentially nefarious user.","status":"published","published":"2021-07-02T13:01:05Z","modified":"2024-08-04T00:47:43Z","updated_at":"2026-11-03T03:24:29.877227Z"}],"ghsa":[{"id":"GHSA-pm9m-mcr8-3v4h","title":"An issue was discovered in the AbuseFilter extension in MediaWiki through 1.36. If the MediaWiki...","description":"An issue was discovered in the AbuseFilter extension in MediaWiki through 1.36. If the MediaWiki:Abusefilter-blocker message is invalid within the content language, the filter user falls back to the English version, but that English version could also be invalid on a wiki. This would result in a fatal error, and potentially fail to block or restrict a potentially nefarious user.","status":"published","published":"2022-05-24T19:06:53Z","modified":"2023-01-30T05:00:37Z","updated_at":"2026-11-02T14:46:14.46933Z"}],"nvd":[{"id":"CVE-2021-36126","description":"An issue was discovered in the AbuseFilter extension in MediaWiki through 1.36. If the MediaWiki:Abusefilter-blocker message is invalid within the content language, the filter user falls back to the English version, but that English version could also be invalid on a wiki. This would result in a fatal error, and potentially fail to block or restrict a potentially nefarious user.","status":"published","published":"2021-07-02T13:15:07.787Z","modified":"2026-06-17T03:58:23.24Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"updated_at":"2026-11-02T14:06:55.259633Z"}],"osv":[{"id":"CVE-2021-36126","description":"An issue was discovered in the AbuseFilter extension in MediaWiki through 1.36. If the MediaWiki:Abusefilter-blocker message is invalid within the content language, the filter user falls back to the English version, but that English version could also be invalid on a wiki. This would result in a fatal error, and potentially fail to block or restrict a potentially nefarious user.","status":"published","published":"2021-07-02T13:15:07.787Z","modified":"2026-10-24T10:30:33.23616273Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:44:20.434873Z"},{"id":"BIT-mediawiki-2021-36126","description":"An issue was discovered in the AbuseFilter extension in MediaWiki through 1.36. If the MediaWiki:Abusefilter-blocker message is invalid within the content language, the filter user falls back to the English version, but that English version could also be invalid on a wiki. This would result in a fatal error, and potentially fail to block or restrict a potentially nefarious user.","status":"published","published":"2024-03-06T11:11:35.468Z","modified":"2025-04-03T14:40:37.652Z","updated_at":"2026-11-02T15:28:33.072289Z"}]}}