What is CVE-2026-35212?

CVE-2026-35212 is a medium-severity vulnerability in Citeum Opencti, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-06-02.

How severe is CVE-2026-35212?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Citeum Opencti

CVE-2026-35212

OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Versions prior to 7.260227.0 are vulnerable to XSS in the rendering of email-message observable body data. The content of the body field isn't appropriately sanitized when being rendered. Does require user interaction but could be exploited by someone sharing stix or any of the ingester. This could lead to CSRF and then large scale session theft. Version 7.260227.0 contains a fix.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.001 (4.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Citeum Opencti
Opencti-platform Opencti — versions < 7.260227.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2026-35212?: CVE-2026-35212 is a medium-severity vulnerability in Citeum Opencti, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-06-02.
How severe is CVE-2026-35212?: Medium severity. CVSS v3 base score is 6.1 out of 10.