CVE-2026-1181: Altium 365 · – Permissive Cross-domain Policy with Untrusted Domains
Affects Altium 365Source CVE Database V5
Not known to be exploited · CVSS 9.0 Critical.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| AltiumAltium 365 | Affected
| Fixed in– |
AI-suggested
European organizations using Altium 365 should immediately audit and restrict the CORS policies on their workspace endpoints to only allow trusted origins with a strict validation mechanism, avoiding wildcard or broad subdomain allowances. They should verify and harden the security posture of all Altium-controlled subdomains, such as forum.live.altium.com, ensuring no additional vulnerabilities exist that could be chained with this issue. Implement Content Security Policy (CSP) headers to limit the execution of untrusted scripts. Review and tighten IP allowlisting configurations and consider additional network segmentation to reduce exposure. Employ multi-factor authentication and monitor API access logs for anomalous or unauthorized activities. Engage with Altium support or security advisories to obtain patches or updates once available. Conduct internal penetration testing focusing on cross-origin interactions and privilege escalation scenarios. Finally, educate users about the risks of interacting with potentially compromised subdomains and enforce least privilege principles for workspace access.
Description
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. As a result, JavaScript executing on those origins could access authenticated workspace APIs in the context of a logged-in user. When chained with vulnerabilities in those external applications, this misconfiguration enables unauthorized access to workspace data, administrative actions, and bypass of IP allowlisting controls, including in GovCloud environments.