CVE-2026-76821Network attack vectorHinoki check available

Authenticated API hang via catastrophic regex backtracking

Published Sep 15, 2026 · Updated Sep 15, 2026

Regular expression denial of service in Filigran OpenCTI before 7.260706.0 allows remote authenticated users to hang the GraphQL API. The extractWithRegexp function in opencti-platform/opencti-graphql/src/parser/json-mapper.ts compiles a user-controlled pattern with JavaScript RegExp without limiting its complexity. JSON mapper creation permission and matching ingestion input are required; scheduled ingestion can repeat the event-loop blockage until the mapper is disabled and the process restarted.

CVSS severityUnavailable
Unscored
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Regular expression denial of service in Filigran OpenCTI before 7.260706.0 allows remote authenticated users to hang the GraphQL API. The extractWithRegexp function in opencti-platform/opencti-graphql/src/parser/json-mapper.ts compiles a user-controlled pattern with JavaScript RegExp without limiting its complexity. JSON mapper creation permission and matching ingestion input are required; scheduled ingestion can repeat the event-loop blockage until the mapper is disabled and the process restarted.

The record

CVE
CVE-2026-76821
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
Filigran
Product
OpenCTI
Classifications
T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 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=< 7.260706.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Filigran · OpenCTIversion=< 7.260706.0

Published CVSS scores

No CVSS assessment is available in this record.

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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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