{"schema_version":1,"title":"Wikimedia Foundation CheckUser vulnerabilities","summary":"Junglewise Threat Intelligence has tracked 3 vulnerabilities in Wikimedia Foundation CheckUser: 0 in the last 7 days and 2 in the last 90 days, 0 of them critical and 0 exploited in the wild. The most recent, CVE-2023-37252, was published on 14 September 2026.","url":"https://junglewise.ai/threats/technologies/checkuser","json_url":"https://junglewise.ai/threats/technologies/checkuser.json","publisher":"Junglewise Threat Intelligence","license":"CC-BY-4.0","license_url":"https://creativecommons.org/licenses/by/4.0/","attribution":"Junglewise Threat Intelligence, https://junglewise.ai/threats/technologies/checkuser","sources":"NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories","kind":"technology","counts":{"high":1,"all_time":3,"critical":0,"exploited":0,"last_7_days":0,"last_30_days":1,"last_90_days":2,"last_365_days":3},"latest":[{"cve":"CVE-2023-37252","cvss":3.1,"epss":0.0024,"slug":"cve-2023-37252-mediawiki-checkuser-extension-information-disclosure-in-log","title":"MediaWiki CheckUser extension information disclosure in log","severity":"low","exploited":false,"published_at":"2026-09-14T05:16:57.58+00:00","url":"https://junglewise.ai/threats/cve-2023-37252-mediawiki-checkuser-extension-information-disclosure-in-log"},{"cve":"CVE-2026-58034","cvss":0,"slug":"cve-2026-58034-wikimedia-foundation-checkuser-xss-in","title":"Wikimedia Foundation CheckUser XSS in blockConnectedTempAccountsField","severity":"info","exploited":false,"published_at":"2026-07-01T15:17:11.15+00:00","url":"https://junglewise.ai/threats/cve-2026-58034-wikimedia-foundation-checkuser-xss-in"},{"cve":"CVE-2026-34090","cvss":7.5,"slug":"cve-2026-34090-wikimedia-foundation-checkuser-information-exposure-in-suggested","title":"Wikimedia Foundation CheckUser information exposure in Suggested Investigations","severity":"high","exploited":false,"published_at":"2026-05-11T16:17:30.407+00:00","url":"https://junglewise.ai/threats/cve-2026-34090-wikimedia-foundation-checkuser-information-exposure-in-suggested"}],"weekly":[{"week":"2026-06-29","critical":0,"exploited":0,"vulnerabilities":1},{"week":"2026-07-06","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-07-13","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-07-20","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-07-27","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-08-03","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-08-10","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-08-17","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-08-24","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-08-31","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-09-07","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-09-14","critical":0,"exploited":0,"vulnerabilities":1},{"week":"2026-09-21","critical":0,"exploited":0,"vulnerabilities":0}],"related":[{"name":"Wikimedia Foundation Mediawiki","slug":"mediawiki","vulnerabilities":20,"url":"https://junglewise.ai/threats/technologies/mediawiki"},{"name":"Wikimedia Foundation Cargo Extension","slug":"cargo-extension","vulnerabilities":4,"url":"https://junglewise.ai/threats/technologies/cargo-extension"},{"name":"Wikimedia Foundation Mediawiki WikiLambda extension","slug":"mediawiki-wikilambda-extension","vulnerabilities":3,"url":"https://junglewise.ai/threats/technologies/mediawiki-wikilambda-extension"}],"technology":{"hub":true,"name":"Wikimedia Foundation CheckUser","slug":"checkuser","vendor":{"name":"Wikimedia Foundation","slug":"wikimedia-foundation","url":"https://junglewise.ai/threats/vendors/wikimedia-foundation"},"aliases":[],"category":"library","homepage":"https://www.mediawiki.org/wiki/Extension:CheckUser","repo_url":"https://github.com/wikimedia/mediawiki-extensions-CheckUser","description":"An extension for MediaWiki that allows users with the appropriate permissions to check which IP addresses are used by a given username.","url":"https://junglewise.ai/threats/technologies/checkuser"},"most_severe":[{"cve":"CVE-2026-34090","cvss":7.5,"slug":"cve-2026-34090-wikimedia-foundation-checkuser-information-exposure-in-suggested","title":"Wikimedia Foundation CheckUser information exposure in Suggested Investigations","severity":"high","exploited":false,"published_at":"2026-05-11T16:17:30.407+00:00","url":"https://junglewise.ai/threats/cve-2026-34090-wikimedia-foundation-checkuser-information-exposure-in-suggested"},{"cve":"CVE-2023-37252","cvss":3.1,"epss":0.0024,"slug":"cve-2023-37252-mediawiki-checkuser-extension-information-disclosure-in-log","title":"MediaWiki CheckUser extension information disclosure in log","severity":"low","exploited":false,"published_at":"2026-09-14T05:16:57.58+00:00","url":"https://junglewise.ai/threats/cve-2023-37252-mediawiki-checkuser-extension-information-disclosure-in-log"},{"cve":"CVE-2026-58034","cvss":0,"slug":"cve-2026-58034-wikimedia-foundation-checkuser-xss-in","title":"Wikimedia Foundation CheckUser XSS in blockConnectedTempAccountsField","severity":"info","exploited":false,"published_at":"2026-07-01T15:17:11.15+00:00","url":"https://junglewise.ai/threats/cve-2026-58034-wikimedia-foundation-checkuser-xss-in"}],"generated_at":"2026-09-27T03:07:00.185062+00:00"}