What is CVE-2026-58054?

CVE-2026-58054 is a high-severity vulnerability in Mybb, classified under Improper Privilege Management. CVSS score: 7.2/10. Published 2026-06-28.

How severe is CVE-2026-58054?

High severity. CVSS v3 base score is 7.2 out of 10.

Privilege escalation in Mybb

CVE-2026-58054

MyBB 1.8.40 does not restrict which usergroup a limited Admin Control Panel user may assign when creating or editing users; the user module offers the Administrators group (gid 4) and its datahandler's verify_usergroup() unconditionally re…

Vulnerability class: Privilege Escalation

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

Affected products

Mybb — versions 0

Weakness classification (CWE)

CWE-269 — Improper Privilege Management

References

disclosure@vulncheck.com (exploit, third-party-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-58054?: CVE-2026-58054 is a high-severity vulnerability in Mybb, classified under Improper Privilege Management. CVSS score: 7.2/10. Published 2026-06-28.
How severe is CVE-2026-58054?: High severity. CVSS v3 base score is 7.2 out of 10.