{"cve":"CVE-2021-31554","nvd":{"published":"2021-04-22T03:15:08.230","modified":"2026-06-17T03:51:59.910","status":"Modified","description":"An issue was discovered in the AbuseFilter extension for MediaWiki through 1.35.2. It improperly handled account blocks for certain automatically created MediaWiki user accounts, thus allowing nefarious users to remain unblocked.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","score":5.4},"cwes":["CWE-863"],"references":["https://gerrit.wikimedia.org/r/q/Ie1f4333d5b1c9d17fb2236fe38a31de427a4cc48","https://phabricator.wikimedia.org/T272244","https://gerrit.wikimedia.org/r/q/Ie1f4333d5b1c9d17fb2236fe38a31de427a4cc48","https://phabricator.wikimedia.org/T272244"],"products":["mediawiki:mediawiki"],"source":"nvd","synced_at":"2026-10-19T21:17:01.373894544+00:00"},"epss":{"cve":"CVE-2021-31554","score":0.00491,"percentile":0.42247,"date":"2026-10-31"},"kev":null,"osv":[],"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."]}