Vulnerability · Published Jan 22, 2026 · Assigned by Altium
CVE-2025-27377Missing Validation of Self-Signed Certificates in Altium Designer Allows Man-in-the-Middle Attacks
Medium 5.3
In plain English
A medium-severity improper certificate validation in Altium Designer from Altium. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities).
Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.2%top 91.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Altium Designer version 24.9.0 does not validate self-signed server certificates for cloud connections. An attacker capable of performing a man-in-the-middle (MITM) attack could exploit this issue to intercept or manipulate network traffic, potentially exposing authentication credentials or sensitive design data.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Altium | Altium Designer | 24.9 – through 25.1 |
Weakness: CWE-295 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N