What is CVE-2026-1181?

CVE-2026-1181 is a critical-severity vulnerability in Altium 365, classified under Permissive Cross-domain Policy with Untrusted Domains. CVSS score: 9.0/10. Published 2026-01-19.

How severe is CVE-2026-1181?

Critical severity. CVSS v3 base score is 9.0 out of 10.

Vulnerability in Altium 365

CVE-2026-1181

Altium 365 workspace endpoints were configured with an overly permissive Cross-Origin Resource Sharing (CORS) policy that allowed credentialed cross-origin requests from other Altium-controlled subdomains, including forum.live.altium.com…

EPSS: 0.000 (8.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H.

Affected products

Altium 365 — versions unspecified

Weakness classification (CWE)

CWE-942 — Permissive Cross-domain Policy with Untrusted Domains
CWE-284 — Improper Access Control

References

www.altium.com/platform/security-compliance/security-advisories

Frequently asked questions

What is CVE-2026-1181?: CVE-2026-1181 is a critical-severity vulnerability in Altium 365, classified under Permissive Cross-domain Policy with Untrusted Domains. CVSS score: 9.0/10. Published 2026-01-19.
How severe is CVE-2026-1181?: Critical severity. CVSS v3 base score is 9.0 out of 10.