---
id: CVE-2026-45124
title: MyBB is free and open source forum software
summary: >-
  MyBB is free and open source forum software. Prior to 1.8.40, the Mod CP
  Report Center does not check permissions consistently, allowing moderators
  without report-management permission to mark reports as resolved. The
  modcp.php?action=do…
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'
cwe:
  - CWE-862
published: '2026-08-18'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T21:02:26.047'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-45124'
references:
  - url: >-
      https://github.com/mybb/mybb/commit/5cda5f6d183bc2cac24f0533e8d3060a9a46cc42
    label: security-advisories@github.com
  - url: 'https://github.com/mybb/mybb/releases/tag/mybb_1840'
    label: security-advisories@github.com
  - url: 'https://github.com/mybb/mybb/security/advisories/GHSA-gfxj-g7w6-6w4v'
    label: security-advisories@github.com
  - url: 'https://mybb.com/versions/1.8.40'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00246
epssPercentile: 0.16227
ingestedAt: '2026-09-08T21:11:12.280Z'
---

## Overview

MyBB is free and open source forum software. Prior to 1.8.40, the Mod CP Report Center does not check permissions consistently, allowing moderators without report-management permission to mark reports as resolved. The modcp.php?action=do_reports Mark Selected as Read handler is reachable with canmodcp even without canmanagereportedcontent or canmanagereportedposts. When no forums are in scope, $flist_reports is empty and the UPDATE mybb_reportedcontent query executes without the expected permission-based limitation. This issue is fixed in version 1.8.40.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.