Cross-Site Scripting and CSRF Vulnerabilities in MyBB Timeline Plugin by MyBB
CVE-2021-47934

6.9MEDIUM

Key Information:

Vendor

Mybb

Status
Mybb Timeline Plugin
Vendor
CVE Published:
16 May 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2021-47934?

The MyBB Timeline Plugin version 1.0 is susceptible to cross-site scripting (XSS) vulnerabilities, which permit attackers to inject harmful scripts via thread titles, post content, and profile fields such as Location and Bio. Additionally, a cross-site request forgery (CSRF) vulnerability allows malicious actors to alter a user's cover picture through the timeline.php profile action by crafting deceptive forms that execute when victims access compromised profiles. This exposure can lead to unauthorized actions performed on behalf of users, compromising account safety and data integrity.

Affected Version(s)

MyBB Timeline Plugin 1.0

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2021-47934 - Proof of Concept

References

https://www.exploit-db.com/exploits/49467
exploit
https://community.mybb.com/mods.php?action=view&pid=1428
product
https://www.vulncheck.com/advisories/mybb-timeline-plugin...
third-party-advisory

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

0xB9
.