Auth bypass in Cisa Malcolm

CVE-2026-107333

Malcolm's nginx based reverse proxy contains a URL path normalization inconsistency between its Lua based role-based access control (RBAC) authorization layer and nginx's own request routing logic. An authenticated user can craft a specially formatted request path to bypass role-based restrictions and reach administrative or role gated endpoints they should not have access to. This affects all restricted paths protected by the RBAC authorization layer, including file upload, PHP server, htadmin, and authentication management interfaces.

Vulnerability class: Broken Access Control

Published .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-107333?
CVE-2026-107333 is a high-severity vulnerability in Cisa Malcolm, classified under Incorrect Authorization. CVSS score: 8.1/10. Published 2026-10-08.
How severe is CVE-2026-107333?
High severity. CVSS v3 base score is 8.1 out of 10.