Unauthenticated thread manipulation via unchecked object IDs
Published Apr 7, 2026 · Updated Apr 7, 2026
Authorization bypass in FreeScout before 1.8.212 allows remote attackers to alter thread read state and enumerate valid thread IDs. The unauthenticated GET /thread/read/{conversation_id}/{thread_id} endpoint looks up the user-controlled thread_id without confirming that it belongs to conversation_id, then writes opened_at. Any network client that can reach the route can distinguish valid IDs through 200-versus-404 responses and modify read metrics across conversations.
Summary
What happened
Authorization bypass in FreeScout before 1.8.212 allows remote attackers to alter thread read state and enumerate valid thread IDs. The unauthenticated GET /thread/read/{conversation_id}/{thread_id} endpoint looks up the user-controlled thread_id without confirming that it belongs to conversation_id, then writes opened_at. Any network client that can reach the route can distinguish valid IDs through 200-versus-404 responses and modify read metrics across conversations.
The record
- CVE
- CVE-2026-35584
- Published
- Apr 7, 2026
- Updated
- Apr 7, 2026
- Vendor
- FreeScout
- Product
- FreeScout
- Classifications
- CWE-639, CWE-306, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 7, 2026CVE publishedPublication date reported by the CVE source.
- Apr 7, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 1.8.212
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- Vendor advisory curl proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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