CVE-2026-1009
Stored XSS in Altium Forum enables JS execution in victim session
Is CVE-2026-1009 being exploited?
Not confirmed. CVE-2026-1009 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.24% probability of exploitation in the next 30 days.
How severe is CVE-2026-1009?
CVE-2026-1009 is rated Critical with a CVSS score of 9.0. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-1009?
Yes. A fix has been recorded for CVE-2026-1009. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-1009 affect?
CVE-2026-1009 affects Altium 365 Platform, Altium Forum. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-1009?
Patch when available; sanitize inputs; limit forum access.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated attacker injects JS via posts; runs in victim's Altium 365 session, accessing design files and workspace settings.
Patch when possible
- affected<= 1.2.2
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.