Auth bypass in Freescout-Help-Desk Freescout

CVE-2026-40592

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.214, the undo-send route `GET /conversation/undo-reply/{thread_id}` checks only whether the current user can view the parent conversation. It does not verify that the current user created the reply being undone. In a shared mailbox, one agent can therefore recall another agent's just-sent reply during the 15-second undo window. Version 1.8.214 fixes the vulnerability.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L.

EPSS exploit prediction

EPSS: 0.004 (27.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 27.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-40592: held from 0.002 to 0.004.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-40592?
CVE-2026-40592 is a medium-severity vulnerability in Freescout-Help-Desk Freescout, classified under Missing Authorization. CVSS score: 5.9/10. Published 2026-04-21.
How severe is CVE-2026-40592?
Medium severity. CVSS v3 base score is 5.9 out of 10.