What is CVE-2021-27948?

CVE-2021-27948 is a high-severity vulnerability in Mybb, classified under SQL Injection. CVSS score: 7.2/10. Published 2021-03-15.

How severe is CVE-2021-27948?

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

SQL Injection in Mybb

CVE-2021-27948

SQL Injection vulnerability in MyBB before 1.8.26 via User Groups. (issue 3 of 3).

Vulnerability class: SQL Injection

Published 2021-03-15 · last modified 2026-06-17.

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.

EPSS exploit prediction

EPSS: 0.009 (58.0th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Mybb

Weakness classification (CWE)

CWE-89 — SQL Injection

References

github.com/mybb/mybb/security/advisories/GHSA-3p9w-2q65-r6g2 (Patch, Third Party Advisory, Release Notes)

Frequently asked questions

What is CVE-2021-27948?: CVE-2021-27948 is a high-severity vulnerability in Mybb, classified under SQL Injection. CVSS score: 7.2/10. Published 2021-03-15.
How severe is CVE-2021-27948?: High severity. CVSS v3 base score is 7.2 out of 10.