OpenctiApplication · Citeum

CVE-2026-35212

MEDIUM · 6.1 CVSS v3.1 Published 2026-06-02
Fix available
A fix is available. Upgrade to 7.260227.0 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

OpenCTI versions prior to 7.260227.0 contain a stored XSS vulnerability in the email-message observable body field rendering. When users view email observables with maliciously crafted body content, the unsanitized data is rendered in the UI, allowing attackers to execute arbitrary JavaScript. Exploitation requires user interaction (viewing the malicious content), which can be achieved through STIX imports or platform ingesters, potentially leading to CSRF attacks and session theft.

MitigationUpgrade OpenCTI to version 7.260227.0 or later to obtain the sanitization fix. Until upgraded, restrict or carefully audit content imported from untrusted STIX bundles and ingester sources.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
OpenctiApplication
Affected:< 7.260227.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check OpenCTI version
    Access the OpenCTI platform and navigate to the version information (usually found in the platform header, about page, or via API endpoint /api/version). Compare the installed version number to 7.260227.0.
    Affected if The installed version is less than 7.260227.0
  2. Identify imported email observables
    Query the platform for any email-message observables. This can be done via the GraphQL API using a query for entities with type 'Email-Message' or via the UI by searching for observables matching the Email-Message pattern.
    Affected if Any email-message observables exist in the platform database
  3. Examine email body content for injection patterns
    Review the body content of imported email-message observables. Look for HTML tags, script elements, javascript: URLs, or other potentially malicious patterns in the body field. Use the platform search or API to retrieve and inspect these fields.
    Affected if Any email-message observable contains unsanitized HTML, script tags, or JavaScript event handlers in the body field that would execute when viewed

The environment is affected if OpenCTI version is below 7.260227.0 and email-message observables with potentially malicious body content have been imported into the platform.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 7.260227.0 or later
Fixed in 7.260227.0
Interim mitigation

Upgrade OpenCTI to version 7.260227.0 or later to obtain the sanitization fix. Until upgraded, restrict or carefully audit content imported from untrusted STIX bundles and ingester sources.

Recommended fix High confidence

7.260227.0

  1. Upgrade OpenCTI to version 7.260227.0 or later to resolve the XSS vulnerability in email-message observable body rendering
  2. Ensure upgrade is performed in a test environment first to validate compatibility with your existing STIX content and ingesters
  3. After upgrade, verify that email-message observable body content is properly sanitized before deploying to production

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Opencti Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-35212 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data