CVE intelligence and bounded remediation

CVE-2026-35212 — OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables

Medium CVSS 6.1

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.

Severity
Medium
CVSS
6.1 (3.1)
Published
2026-06-02
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-79

Affected products

  • citeum / opencti

Matched remediation archetype

Cross-site scripting and unsafe browser output

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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