CVE-2026-35212

Description

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.

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CVSS v3.1 Score

6.1

MEDIUM

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

EPSS — Exploit Prediction

0.0015

Probability of exploitation

0.04%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

Affected Products

Vendor	Product	Versions
citeum	opencti	< 7.260227.0

References

Advisories & Patches

https://github.com/OpenCTI-Platform/opencti/security/advisories/GHSA-rg6r-x26x-63vq

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 6.1 (MEDIUM).

How severe is CVE-2026-35212? +

CVE-2026-35212 has a CVSS v3.1 score of 6.1 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0015, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-35212? +

CVE-2026-35212 affects products from citeum, specifically: opencti. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-35212? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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