Comment author spoofing via unchecked comment_by parameter
Published Sep 16, 2026 · Updated Sep 16, 2026
Improper authorization in FluentBoards before 2.0.15 allows remote authenticated users to post comments attributed to other users. The comment creation endpoint accepts a client-supplied comment_by user ID and records that identity without verifying it matches the authenticated requester. Board membership is required, and a successful request can make attacker-controlled text appear to come from another member, including an administrator.
Summary
What happened
Improper authorization in FluentBoards before 2.0.15 allows remote authenticated users to post comments attributed to other users. The comment creation endpoint accepts a client-supplied comment_by user ID and records that identity without verifying it matches the authenticated requester. Board membership is required, and a successful request can make attacker-controlled text appear to come from another member, including an administrator.
The record
- CVE
- CVE-2026-89327
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- Mahmudul Hasan Arif
- Product
- FluentBoards
- Classifications
- T1036
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 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=0 <2.0.15
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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