CVE-2026-76821
Received
Received - Intake
ReDoS in OpenCTI JSON Mapper via Catastrophic Backtracking
Vulnerability report for CVE-2026-76821, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-15
Last updated on: 2026-09-15
Assigner: GitHub, Inc.
Description
Description
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 7.260706.0, the JSON ingestion mapper's extractWithRegexp formula function compiled a user-supplied regular expression with the JavaScript RegExp engine in opencti-platform/opencti-graphql/src/parser/json-mapper.ts without validating its complexity. An authenticated user with JSON mapper creation permission could provide a catastrophically backtracking pattern and matching ingestion input, blocking the Node.js event loop and making the GraphQL API unavailable to all users. Scheduled ingestion could repeatedly execute the malicious mapper without additional attacker action, and recovery could require disabling the mapper and restarting the process. The issue affects availability and does not expose or modify data. This issue is fixed in version 7.260706.0.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| opencti | opencti | to 7.260706.0 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-400 | The product does not properly control the allocation and maintenance of a limited resource. |
| CWE-1333 | The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles. |
