CVE-2026-76821CWE-1333CWE-400denial-of-service

CVE-2026-76821

published September 16, 2026

CVSS
7.1
EPSS
0%
Percentile
39.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS
7.1 · NONE
CVSS v4.0
7.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
EPSS
0.00466 · 39.4th percentile
Weaknesses
CWE-1333 · Inefficient Regular Expression Complexity; CWE-400 · Uncontrolled Resource Consumption
Published
2026-09-16T00:17Z
References (4)
EPSS history
Timeline
  • 17 SEP 03:32Z
    EPSS moved — → 0%
    epss
  • 15 SEP 19:38Z
    OpenCTI: User-Controlled ReDoS in JSON Ingestion Mapper
    cvelistv5