Path Traversal in Mybb

CVE-2023-53979

MyBB 1.8.32 contains a chained vulnerability that allows authenticated administrators to bypass avatar upload restrictions and execute arbitrary code. Attackers can modify upload path settings, upload a malicious PHP-embedded image file, and execute commands through the language configuration editing interface.

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.007 (50.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

  • Mybb — versions 1.8.32, MyBB 1.8.32

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-53979?
CVE-2023-53979 is a high-severity vulnerability in Mybb, classified under Path Traversal. CVSS score: 8.8/10. Published 2025-12-22.
How severe is CVE-2023-53979?
High severity. CVSS v3 base score is 8.8 out of 10.