CVE-2023-53979

MyBB 1.8.32 Authenticated Remote Code Execution via Chained Vulnerabilities

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.

Affected

Mybb · MyBB

CVSS v4.0 VULNCHECK

8.6 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 VULNCHECK

8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

0.82% chance of exploitation in the next 30 days, 56th percentile

Published

2025-12-22

Updated

2026-03-05

Proof-of-concept exploits (1)

• https://www.exploit-db.com/exploits/51213

Security advisories

• https://fdlucifer.github.io/2023/01/17/mybb1-8-32-LFI-RCE
• https://www.vulncheck.com/advisories/mybb-authenticated-remote-code-execution-via-chained…
• https://mybb.com

References

• CVE Record
• NVD entry