PT-2026-34026 · Freescout · Freescout

CVE-2026-40591 · Published 2026-04-21 · Updated 2026-04-27

Positive Technologies (AI Summary)

CVSS v3.1

7.1

High

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

Name of the Vulnerable Software and Affected Versions FreeScout versions prior to 1.8.214

Description The phone-conversation creation flow allows the use of attacker-controlled customer id, name, to email, and phone values. The system resolves the target customer in the backend without enforcing mailbox-scoped customer visibility. This enables a low-privileged agent with permissions to create a phone conversation in one mailbox to bind that conversation to a hidden customer from another mailbox and add a new alias email to the hidden customer record via the to email parameter.

Recommendations Update to version 1.8.214.

Exploit

Fix

IDOR

Weakness Enumeration

CWE-639

Related Identifiers

CVE-2026-40591

GHSA-9FF4-MMHV-X6JP

Affected Products

Freescout

References · 8

• 🔥 https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-9ff4-mmhv-x6jp · Exploit
• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40591.json · Exploit
• https://osv.dev/vulnerability/CVE-2026-40591 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-40591 · Security Note
• https://github.com/freescout-help-desk/freescout/releases/tag/1.8.214 · Note
• https://github.com/freescout-help-desk/freescout/commit/83eea1ca47d97c6cdc90c501734bc2579b014a34 · Note
• https://twitter.com/CVEnew/status/2048910161822289946 · Twitter Post
• https://twitter.com/infoflowcloud/status/2048911689895051573 · Twitter Post