Draft creation via resend CSRF
Published Aug 18, 2026 · Updated Aug 19, 2026
Cross-site request forgery in the ACP Mass Mail module in MyBB before 1.8.40 allows attackers to create draft mailings via a crafted URL. In admin/modules/user/mass_mail.php, the action=resend handler copies an archived mass-mail entry into a new mybb_massemails record with status 0 on a GET request and performs no verify_post_check token validation. Exploitation requires a victim with access to the Admin CP Mass Mailing Archive to follow or load attacker-controlled content; the effect is limited to unauthorized draft creation rather than direct message sending or deletion.
Summary
What happened
Cross-site request forgery in the ACP Mass Mail module in MyBB before 1.8.40 allows attackers to create draft mailings via a crafted URL. In admin/modules/user/mass_mail.php, the action=resend handler copies an archived mass-mail entry into a new mybb_massemails record with status 0 on a GET request and performs no verify_post_check token validation. Exploitation requires a victim with access to the Admin CP Mass Mailing Archive to follow or load attacker-controlled content; the effect is limited to unauthorized draft creation rather than direct message sending or deletion.
The record
- CVE
- CVE-2026-45127
- Published
- Aug 18, 2026
- Updated
- Aug 19, 2026
- Vendor
- MyBB
- Product
- MyBB
- Classifications
- CWE-352
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Aug 18, 2026CVE publishedPublication date reported by the CVE source.
- Aug 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 1.8.40
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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