CVE-2018-25309 PUBLISHED

MyBB Recent threads 17.0 Persistent Cross-Site Scripting

Assigner: VulnCheck
Reserved: 29.04.2026 Published: 29.04.2026 Updated: 29.04.2026

MyBB Recent threads 17.0 contains a persistent cross-site scripting vulnerability that allows attackers to inject malicious scripts by creating threads with crafted subject lines. Attackers can create threads with script tags in the subject parameter to execute arbitrary JavaScript in the browsers of all users viewing the index page.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
CVSS Score: 5.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	Low
Attack Complexity	Low	Integrity	None	Integrity	Low
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	Low
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
CVSS Score: 7.2

Attack Vector	Network	Scope	Changed
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	Low
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	mybb
Product	MyBB Recent threads
Versions	Version 17.0 is affected

Credits

Perileos finder

References

Problem Types

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CWE