CVE-2023-53977Public exploitNetwork attack vector

Stored script execution via unsanitized forum titles

Published Dec 22, 2025 · Updated Dec 22, 2025

Stored XSS in MyBB 1.8.26 forum management allows remote authenticated users to execute JavaScript through a crafted forum title. The add-forum handler stores the title parameter, and the forum-management listing returns it in link text without HTML output encoding. Administrator access is required, and execution occurs only when the forum-management listing is viewed in a browser.

CVSS severity5.1
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stored XSS in MyBB 1.8.26 forum management allows remote authenticated users to execute JavaScript through a crafted forum title. The add-forum handler stores the title parameter, and the forum-management listing returns it in link text without HTML output encoding. Administrator access is required, and execution occurs only when the forum-management listing is viewed in a browser.

The record

CVE
CVE-2023-53977
Published
Dec 22, 2025
Updated
Dec 22, 2025
Vendor
MyBB
Product
MyBB
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Dec 22, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 22, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.8.26

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

MyBB · MyBBversion=1.8.26

Published CVSS scores

5.4VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
5.1VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript/JScript

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo