CVE-2026-35212Network attack vector

Session theft via unsanitized email body rendering

Published Jun 2, 2026 · Updated Jun 2, 2026

Stored XSS in Filigran OpenCTI before 7.260227.0 allows remote attackers to execute script in a user's browser through email-message body data. The email-message observable view renders the body field without appropriate sanitization, preserving attacker-supplied active content. A user must open the crafted observable after it is shared through STIX or an ingester; script execution can forge requests and steal sessions at scale.

CVSS severity5.3
Medium
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Filigran OpenCTI before 7.260227.0 allows remote attackers to execute script in a user's browser through email-message body data. The email-message observable view renders the body field without appropriate sanitization, preserving attacker-supplied active content. A user must open the crafted observable after it is shared through STIX or an ingester; script execution can forge requests and steal sessions at scale.

The record

CVE
CVE-2026-35212
Published
Jun 2, 2026
Updated
Jun 2, 2026
Vendor
Filigran
Product
OpenCTI
Classifications
CWE-79, T1539, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 2, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 7.260227.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Filigran · OpenCTIversion=< 7.260227.0

Published CVSS scores

5.3GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1539Steal Web Session Cookie
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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