An issue in MyBB 1.8.38 allows a remote attacker to obtain sensitive information via the Add Mycode function. NOTE: the Supplier disputes this because of the allowed actions of Board administrators and because of SSRF mitigation.
CVSS Score
7.6
EPSS Score
0.002
Published
2025-04-17
A stored cross-site scripting (XSS) vulnerability in the component install\index.php of MyBB v1.8.38 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the Website Name parameter. NOTE: this is disputed by the Supplier because Website Name can only be set by an administrator, who may use JavaScript if they wish.
CVSS Score
5.4
EPSS Score
0.006
Published
2024-11-20
MyBB is a free and open source forum software. The backup management module of the Admin CP may accept `.htaccess` as the name of the backup file to be deleted, which may expose the stored backup files over HTTP on Apache servers. MyBB 1.8.38 resolves this issue. Users are advised to upgrade. There are no known workarounds for this vulnerability
CVSS Score
4.7
EPSS Score
0.002
Published
2024-05-01
MyBB is a free and open source forum software. The default list of disallowed remote hosts does not contain the `127.0.0.0/8` block, which may result in a Server-Side Request Forgery (SSRF) vulnerability. The Configuration File's _Disallowed Remote Addresses_ list (`$config['disallowed_remote_addresses']`) contains the address `127.0.0.1`, but does not include the complete block `127.0.0.0/8`. MyBB 1.8.38 resolves this issue in default installations. Administrators of installed boards should update the existing configuration (`inc/config.php`) to include all addresses blocked by default. Additionally, users are advised to verify that it includes any other IPv4 addresses resolving to the server and other internal resources. Users unable to upgrade may manually add 127.0.0.0/8' to their disallowed address list.
CVSS Score
5.0
EPSS Score
0.001
Published
2024-05-01
Cross Site Scripting vulnerability in Mybb Mybb Forums v.1.8.33 allows a local attacker to execute arbitrary code via the theme Name parameter in the theme management component.
CVSS Score
5.4
EPSS Score
0.002
Published
2023-11-06
MyBB is a free and open source forum software. Custom MyCode (BBCode) for the visual editor (_SCEditor_) doesn't escape input properly when rendering HTML, resulting in a DOM-based XSS vulnerability. This weakness can be exploited by pointing a victim to a page where the visual editor is active (e.g. as a post or Private Message) and operates on a maliciously crafted MyCode message. This may occur on pages where message content is pre-filled using a GET/POST parameter, or on reply pages where a previously saved malicious message is quoted. The impact is be mitigated when: 1. the visual editor is disabled globally (_Admin CP → Configuration → Settings → Clickable Smilies and BB Code: [Clickable MyCode Editor](https://github.com/mybb/mybb/blob/mybb_1836/install/resources/settings.xml#L2087-L2094)_ is set to _Off_), or 2. the visual editor is disabled for individual user accounts (_User CP → Your Profile → Edit Options_: _Show the MyCode formatting options on the posting pages_ checkbox is not checked). MyBB 1.8.37 resolves this issue with the commit `6dcaf0b4d`. Users are advised to upgrade. Users unable to upgrade may mitigate the impact without upgrading MyBB by changing the following setting (_Admin CP → Configuration → Settings_):
- _Clickable Smilies and BB Code → [Clickable MyCode Editor](https://github.com/mybb/mybb/blob/mybb_1836/install/resources/settings.xml#L2087-L2094)_: _Off_. Similarly, individual MyBB forum users are able to disable the visual editor by diabling the account option (_User CP → Your Profile → Edit Options_) _Show the MyCode formatting options on the posting pages_.
CVSS Score
7.5
EPSS Score
0.005
Published
2023-11-06
Installer RCE on settings file write in MyBB before 1.8.22.
CVSS Score
9.8
EPSS Score
0.001
Published
2023-09-01
MyBB before 1.8.36 allows Code Injection by users with certain high privileges. Templates in Admin CP intentionally use eval, and there was some validation of the input to eval, but type juggling interfered with this when using PCRE within PHP.
CVSS Score
7.2
EPSS Score
0.22
Published
2023-08-29
In MyBB before 1.8.34, there is XSS in the User CP module via the user email field.
CVSS Score
6.1
EPSS Score
0.001
Published
2023-05-22
MyBB before 1.8.33 allows Directory Traversal. The Admin CP Languages module allows remote authenticated users, with high privileges, to achieve local file inclusion and execution.
CVSS Score
7.2
EPSS Score
0.01
Published
2023-01-03