SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-11423

A path traversal vulnerability exists in the Altium Enterprise Server Collaboration Service due to improper handling of user-supplied filenames in the MCAD and Simulation file download flows.

CRITICAL 9.4EPSS 0.32%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.32%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

A path traversal vulnerability exists in the Altium Enterprise Server Collaboration Service due to improper handling of user-supplied filenames in the MCAD and Simulation file download flows. A regular authenticated user can submit a collaboration message containing a crafted filename, which is later used to construct the download path on the server without validation, allowing arbitrary files to be read from the server filesystem. Because the readable files include the server's master configuration, which stores credentials for privileged accounts, exploitation can lead to authenticating as a system administrator and gaining full control of the server. Altium 365 cloud deployments are not affected.

CVSS 4.0
9.4 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.32% probability · 25th percentile
CISA KEV
Not listed
Weakness
CWE-22, CWE-269
Source
4760f414-e1ae-4ff1-bdad-c7a9c3538b79

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.