Description
MyBB is a free and open source forum software. The _Mail Settings_ → Additional Parameters for PHP's mail() function mail_parameters setting value, in connection with the configured mail program's options and behavior, may allow access to sensitive information and Remote Code Execution (RCE). The vulnerable module requires Admin CP access with the `_Can manage settings?_` permission and may depend on configured file permissions. MyBB 1.8.31 resolves this issue with the commit `0cd318136a`. Users are advised to upgrade. There are no known workarounds for this vulnerability.
References (4)
Core 4
Core References
Exploit, Third Party Advisory
https://github.com/mybb/mybb/blob/mybb_1830/install/resources/settings.xml#L2331-L2338
Patch, Third Party Advisory
https://github.com/mybb/mybb/commit/0cd318136a10b029bb5c8a8f6dddf39d87519797
Third Party Advisory
https://github.com/mybb/mybb/security/advisories/GHSA-hxhm-rq9f-7xj7
Release Notes, Vendor Advisory
https://mybb.com/versions/1.8.31/
Scores
CVSS v3
7.2
EPSS
0.0471
EPSS Percentile
89.4%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
total
Details
CWE
CWE-74
CWE-77
Status
published
Products (1)
mybb/mybb
< 1.8.31
Published
Oct 06, 2022
Tracked Since
Feb 18, 2026