CVE-2026-39980 OpenCTI affected by RCE via notifier template
Attackers with customization rights can execute arbitrary JavaScript via unsanitized EJS templates in OpenCTI notifier configurations.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-39980?
CVE-2026-39980 is a critical code injection vulnerability in OpenCTI-Platform opencti, published on 9 Apr 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 6.9.5, the safeEjs.ts file does not properly sanitize EJS templates. Users with the Manage customization capability can run arbitrary JavaScript in the context of the OpenCTI platform process during notifier template execution. This vulnerability is fixed in 6.9.5.
Weakness: CWE-1336
Which versions are affected by CVE-2026-39980?
1 open source package ship an affected version, including pycti. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
pycti PyPI | All versions | 6.9.5 |
Products include Citeum Opencti.
How do I fix CVE-2026-39980?
Upgrade pycti to 6.9.5 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-39980 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39980 exists.
Public exploit code: 1 Metasploit module.
Other vulnerabilities in OpenCTI-Platform opencti
- CVE-2026-27960 OpenCTI privilege escalation and unauthenticated access via default admin account
- CVE-2025-24977 OpenCTI has remote code execution and sensitive secrets exposed through web hook
- CVE-2024-26139 OpenCTI Authenticated Privilege Escalation
- CVE-2024-45404 OpenCTI's lack of Rate Limit lead to OTP brute forcing
- CVE-2026-21887 OpenCTI has a Semi-Blind SSRF via Unvalidated External URL in Data Ingestion Feature
Sources
Also known as GHSA-jv9r-jw2f-rhrf, PYSEC-2026-2265.