{"cve":"CVE-2021-27279","nvd":{"published":"2021-02-22T20:15:13.243","modified":"2026-06-17T03:44:36.427","status":"Modified","description":"MyBB before 1.8.25 allows stored XSS via nested [email] tags with MyCode (aka BBCode).","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","score":5.4},"cwes":["CWE-79"],"references":["https://github.com/mybb/mybb/commit/cb781b49116bf5c4d8deca3e17498122b701677a","https://github.com/mybb/mybb/security/advisories/GHSA-6483-hcpp-p75w","https://mybb.com/versions/1.8.25/","https://github.com/mybb/mybb/commit/cb781b49116bf5c4d8deca3e17498122b701677a","https://github.com/mybb/mybb/security/advisories/GHSA-6483-hcpp-p75w"],"products":["mybb:mybb"],"source":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-27279","score":0.00959,"percentile":0.6153,"date":"2026-11-01"},"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."]}