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TI-2026-32952 Aliases CVE-2026-45119

MyBB: ACP UTF-8 Conversion CSRF

Priority LOW 20CWE-352Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Required
Attack complexity
Low
Impact type
Tampering
Confidentiality · integrity · availability
None · Low · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-352.

Summary

MyBB is free and open source forum software. Prior to 1.8.40, the Admin CP UTF-8 Conversion module does not validate certain requests correctly, allowing same-site attackers to alter table encoding and deny service with a specially crafted URL. The do=all control flow in admin/modules/tools/system_health.php performs ALTER TABLE operations, column rewrite phases, and fulltext index rebuilds on GET requests for the database table named by the table parameter without request verification. The uniquely identifying implementation details include GET requests without request verification. This issue is fixed in version 1.8.40.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00168 6th percentileScored 2026-11-07
Fix Fixed mybb (mybb): 1.8.40

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
mybbmybbbefore 1.8.401.8.40Patch availableCNA
  • mybb Vendormybb Affected before 1.8.40 Fixed in 1.8.40 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:mybb:mybb:*:*:*:*:*:*:*:*——mybb
  • cpe:2.3:a:mybb:mybb:*:*:*:*:*:*:*:* Versions — — ·mybb

Remediation

  • Fix · CNA mybb (mybb) Fixed in 1.8.40

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-45119

References

Other 4

  • TI-2011-04621 myBB 1.6.4 Backdoor Arbitrary Command Execution CVSS 4.0CRITICAL 10.0
  • TI-2022-08548 Remote code execution in mybb CVSS 3.1HIGH 7.2
  • TI-2021-22547 MyBB Timeline Plugin 1.0 Cross-Site Scripting and CSRF CVSS 4.0MEDIUM 6.9
  • TI-2023-21959 MyBB before 1.8.36 allows Code Injection by users with certain high privileges. CVSS 3.1HIGH 7.2
  • TI-2022-18641 Mail settings' command parameter injection in mybb CVSS 3.1HIGH 7.2
  • TI-2025-21092 An issue in MyBB 1.8.38 allows a remote attacker to obtain sensitive information via the… CVSS 3.1HIGH 7.6
See all 173 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences