CVE-2026-1009 Stored Cross-Site Scripting in Altium Live Forum Leading to Cross-Customer Data Exposure
An authenticated attacker can inject JavaScript into forum posts to steal workspace data and hijack sessions of other users viewing the post.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-1009?
CVE-2026-1009 is a critical cross-site scripting vulnerability in Altium Live, published on 15 Jan 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
A stored cross-site scripting (XSS) vulnerability exists in the Altium Forum due to missing server-side input sanitization in forum post content. An authenticated attacker can inject arbitrary JavaScript into forum posts, which is stored and executed when other users view the affected post. Successful exploitation allows the attacker’s payload to execute in the context of the victim’s authenticated Altium 365 session, enabling unauthorized access to workspace data, including design files and workspace settings. Exploitation requires user interaction to view a malicious forum post.
Which versions are affected by CVE-2026-1009?
It affects 1 product.
Products include Altium Altium Live.
How do I fix CVE-2026-1009?
No fix has been published for CVE-2026-1009 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-1009 being exploited?
There is no known exploitation of CVE-2026-1009 in the wild and no public exploit code.
Other vulnerabilities in Altium Live
Sources
Also known as GHSA-fc5v-qvgj-pv25.