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TI-2026-53665 Aliases CVE-2026-76821

OpenCTI: User-Controlled ReDoS in JSON Ingestion Mapper

Priority LOW 32CWE-1333Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-1333.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00466 40th percentileScored 2026-11-07
Fix Fixed opencti (OpenCTI-Platform): 7.260706.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
OpenCTI-Platformopenctibefore 7.260706.07.260706.0Patch availableCNA
  • opencti VendorOpenCTI-Platform Affected before 7.260706.0 Fixed in 7.260706.0 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:citeum:opencti:*:*:*:*:*:*:*:*——OpenCTI-Platform

Remediation

  • Fix · CNA opencti (OpenCTI-Platform) Fixed in 7.260706.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-76821

References

Other 4

  • TI-2024-24682 OpenCTI May Bypass Introspection Restriction CVSS 3.1HIGH 8.2
  • TI-2024-30453 OpenCTI's lack of Rate Limit lead to OTP brute forcing CVSS 3.1HIGH 8.1
  • TI-2020-19176 OpenCTI 3.3.1 - Directory Traversal CVSS 4.0HIGH 7.1
  • TI-2026-22303 OpenCTI privilege escalation and unauthenticated access via default admin account CVSS 3.1CRITICAL 9.8
  • TI-2020-19179 OpenCTI 3.3.1 - Cross Site Scripting CVSS 4.0MEDIUM 5.1
  • TI-2024-30771 OpenCTI leaks support information due to inadequate access control CVSS 3.1MEDIUM 4.3
See all 23 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences