CVE-2026-76821

OpenCTI: User-Controlled ReDoS in JSON Ingestion Mapper

HIGH
7.1
CVSS Score
Published: September 15, 2026 at 07:38 PM UTC
Updated: September 30, 2026 at 05:43 PM UTC
1 product affected across 1 vendorOpencti

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Severity
HIGH7.1
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 7.260706.0
Affected range stops below 7.260706.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.1HIGHGitHub_M
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-400CWE-1333

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