{"id":"CVE-2026-34091","aliases":["DEBIAN-CVE-2026-34091","EUVD-2026-29063","GHSA-7gvw-7r69-cgx7","UBUNTU-CVE-2026-34091"],"status":"published","title":"User localization leaked by AbuseFilter + EventStream","description":"Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki.\n\nThis issue affects MediaWiki: from * before 1.43.7, 1.44.4, 1.45.2.","severity":{"version":"4.0","score":5.5,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/R:U","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.0029,"percentile":0.21704,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-200"],"published":"2026-05-11T14:55:33Z","modified":"2026-10-28T02:30:40Z","fixes":[{"ecosystem":"Debian:13","package":"mediawiki","fixed_in":["1:1.43.8+dfsg-1~deb13u1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"mediawiki","fixed_in":["1:1.43.8+dfsg-1"],"sources":["osv"]},{"ecosystem":"Ubuntu:26.04:LTS","package":"mediawiki","fixed_in":["1:1.43.8+dfsg-2"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:13","package":"mediawiki","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:1.43.8+dfsg-1~deb13u1"}]}],"versions":["1:1.43.3+dfsg-1","1:1.43.5+dfsg-1","1:1.43.6+dfsg-1","1:1.43.6+dfsg-1~deb13u1","1:1.43.6+dfsg-2"]},{"source":"osv","ecosystem":"Debian:14","package":"mediawiki","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:1.43.8+dfsg-1"}]}],"versions":["1:1.43.3+dfsg-1","1:1.43.5+dfsg-1","1:1.43.6+dfsg-1","1:1.43.6+dfsg-1~deb13u1","1:1.43.6+dfsg-2","1:1.43.8+dfsg-1~deb13u1"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"mediawiki","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:1.43.1+dfsg-1","1:1.43.1+dfsg-2","1:1.43.3+dfsg-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"mediawiki","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:1.43.8+dfsg-2"}]}],"versions":["1:1.43.3+dfsg-1","1:1.43.5+dfsg-1","1:1.43.6+dfsg-2","1:1.43.8+dfsg-1"]}],"products":[{"vendor":"mediawiki","product":"mediawiki"},{"vendor":"wikimedia foundation","product":"mediawiki"}],"references":[{"url":"https://phabricator.wikimedia.org/T411305","tags":["Issue Tracking","Vendor Advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34091"},{"url":"https://github.com/advisories/GHSA-7gvw-7r69-cgx7"},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-34091","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-34091","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-34091","tags":["report"]},{"url":"https://gerrit.wikimedia.org/r/c/mediawiki/core/+/1265651","tags":["report"]},{"url":"https://gerrit.wikimedia.org/r/c/mediawiki/core/+/1265637","tags":["report"]},{"url":"https://lists.wikimedia.org/hyperkitty/list/wikitech-l@lists.wikimedia.org/thread/DIBLSBHISKX6NFRUFNOGZRVW42E7R2QP/","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-34091","title":"User localization leaked by AbuseFilter + EventStream","description":"Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki.\n\nThis issue affects MediaWiki: from * before 1.43.7, 1.44.4, 1.45.2.","status":"published","published":"2026-05-11T14:55:33.419Z","modified":"2026-05-11T16:03:07.32Z","cvss":[{"version":"4.0","score":5.5,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/R:U","level":"medium","assessor":"cna"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T14:20:14.302133Z"}],"euvd":[{"id":"EUVD-2026-29063","description":"Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki.\n\nThis issue affects MediaWiki: from * before 1.43.7, 1.44.4, 1.45.2.","status":"published","published":"2026-05-11T14:55:33Z","modified":"2026-05-11T16:03:07Z","cvss":[{"version":"4.0","score":5.5,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/R:U","level":"medium"}],"updated_at":"2026-11-02T19:05:10.736891Z"}],"ghsa":[{"id":"GHSA-7gvw-7r69-cgx7","title":"Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation...","description":"Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki.\n\nThis issue affects MediaWiki: from * before 1.43.7, 1.44.4, 1.45.2.","status":"published","published":"2026-05-11T18:31:43Z","modified":"2026-05-14T18:33:54Z","cvss":[{"version":"4.0","score":5.5,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:U/V:X/RE:X/U:X","level":"medium"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T15:08:08.953643Z"}],"nvd":[{"id":"CVE-2026-34091","description":"Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki.\n\nThis issue affects MediaWiki: from * before 1.43.7, 1.44.4, 1.45.2.","status":"published","published":"2026-05-11T16:17:30.537Z","modified":"2026-10-26T18:10:00.173Z","cvss":[{"version":"4.0","score":5.5,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:U/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high","assessor":"primary"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T14:12:18.239974Z"}],"osv":[{"id":"CVE-2026-34091","description":"Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki.\n\nThis issue affects MediaWiki: from * before 1.43.7, 1.44.4, 1.45.2.","status":"published","published":"2026-05-11T16:17:30.537Z","modified":"2026-10-28T02:30:40.735452513Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"updated_at":"2026-11-02T15:45:02.247031Z"},{"id":"DEBIAN-CVE-2026-34091","description":"Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki.  This issue affects MediaWiki: from * before 1.43.7, 1.44.4, 1.45.2.","status":"published","published":"2026-05-11T16:17:30.537Z","modified":"2026-10-27T09:47:29.35772623Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"updated_at":"2026-11-02T15:45:54.587575Z"},{"id":"UBUNTU-CVE-2026-34091","description":"Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki. This issue affects MediaWiki: from * before 1.43.7, 1.44.4, 1.45.2.","status":"published","published":"2026-05-11T16:17:00Z","modified":"2026-05-26T07:30:15.321572468Z","cvss":[{"version":"4.0","score":5.5,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/R:U","level":"medium"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"updated_at":"2026-11-02T16:56:16.036833Z"}]}}