SEPTEMBER 19, 2026
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Case File

CVE-2026-45115

HIGH · CVSS 8.7 EPSS 0.29% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-08-18 · Last synced 2026-09-17

CyberRota Analysis

AI-Generated

The Buddy/Ignore component in MyBB forum software versions prior to 1.8.40 is vulnerable to JavaScript code injection due to improper sanitization of usernames, specifically leaving single quotes unescaped. This vulnerability can be exploited when users interact with the user control panel or private message features, potentially allowing attackers to execute malicious scripts in the context of a victim's session. Organizations using affected versions of MyBB should prioritize upgrading to version 1.8.40 to mitigate this high-severity risk.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-45115
Severity
HIGH
CVSS
8.7
EPSS
0.29%
Java

Original NVD Description

MyBB is free and open source forum software. Prior to 1.8.40, the Buddy/Ignore component does not sanitize usernames correctly, allowing attackers to perform JavaScript code injection through a specially crafted username. The User CP Buddy/Ignore list and the Select Buddies list in Private Messages pass usernames through htmlspecialchars_uni(), which may leave single quotes unescaped. The payload is triggered when a victim chooses Yes in Please Confirm while removing the username in usercp.php, or selects the username through the onclick handler in the xmlhttp.php Select Buddies popup. The uniquely identifying implementation details include Private Messages Select Buddies list, and unescaped single quotes. This issue is fixed in version 1.8.40.