Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:LSummary
CVE-2026-39384 is a high-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Freescout Freescout. Its CVSS base score is 7.6 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 15th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-3 (Access Enforcement) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-39384 is an authorization bypass vulnerability in FreeScout, a free help desk and shared inbox application built with PHP's Laravel framework. In versions prior to 1.8.212, FreeScout does not properly consider the limit_user_customer_visibility parameter when performing customer merging operations. This flaw, classified under CWE-639 (Authorization Bypass Through User-Controlled Key), carries a CVSS v3.1 base score of 7.6 (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L).
An attacker with low privileges, such as an authenticated user, can exploit this vulnerability remotely over the network with low complexity and no user interaction required. By initiating a customer merge operation, the attacker bypasses visibility restrictions, potentially gaining unauthorized access to limited customer data (low confidentiality impact), performing high-impact integrity modifications like altering customer associations, and causing limited availability disruption.
The issue is fixed in FreeScout version 1.8.212. Administrators should upgrade to this release or later to mitigate the vulnerability. Official details are provided in the GitHub security advisory GHSA-j6v9-22vq-53vh and the fixing commit b395a1179117af5e2df704c6bad71feeb301b4ce.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-19740
Vulnerability Data
FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to 1.8.212, FreeScout does not take the limit_user_customer_visibility parameter into account when merging customers. This vulnerability is fixed in 1.8.212.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Enforcing approved authorizations on every access request structurally stops a user-controlled key from reaching another user's data.
Requiring explicit access-control decisions on each request blocks unauthorized key-driven access.
Least-privilege restrictions limit the scope of data reachable even if a key check is bypassed.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Enforcing authorization policy and least privilege directly blocks user-controlled key tampering that bypasses access checks.
Logical access controls prevent unauthorized data access that results from missing authorization checks on object references.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect missing authorization checks but does not prevent the weakness in production.
Information access restriction explicitly enforces that users may only retrieve data they are authorized to see, directly addressing user-controlled key bypass.
Access control policy directly requires enforcement of authorization rules that prevent unauthorized access via manipulated keys.
Managing access rights includes ensuring users can only access their own records and not bypass authorization by altering identifiers.
Privileged access rights control restricts what data each user may access, mitigating direct object reference attacks.
Secure development lifecycle includes authorization design but does not itself implement runtime access checks.