CVE-2026-35584: FreeScout has an Unauthenticated IDOR in Open Tracking Endpoint Allows Cross-Conversation Thread Manipulation and Enumeration

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-04-07 · updated 2026-06-17
Weakness: CWE-306

Description

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to 1.8.212, the endpoint GET /thread/read/{conversation_id}/{thread_id} does not require authentication and does not validate whether the given thread_id belongs to the given conversation_id. This allows any unauthenticated attacker to mark any thread as read by passing arbitrary IDs, enumerate valid thread IDs via HTTP response codes (200 vs 404), and manipulate opened_at timestamps across conversations (IDOR). This vulnerability is fixed in 1.8.212.

Affected products

freescout-help-desk freescout: before 1.8.212 — fixed in 1.8.212

How to fix

Upgrade to a fixed version: freescout-help-desk freescout 1.8.212. Check the vendor advisory for mitigations.

References

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