← Vulnerability feed

Vulnerability record · CVE-2026-76821 · published 15 September 2026

CVE-2026-76821: Uncontrolled resource consumption vulnerability

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.

7.1 CVSS 4.0 High EPSS 0.47% · top 62.2% CWE-400 · Uncontrolled resource consumptionCWE-1333 · Inefficient regular expression (ReDoS) Received
7.1CVSS 4.0 base score
0.47%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
4References
16 Sep 2026Last modified by NVD

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:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

References

LinkTags
https://github.com/OpenCTI-Platform/opencti/commit/3d726c09480f96980ce4c3e6119a8034dbdf2c96
https://github.com/OpenCTI-Platform/opencti/pull/16935
https://github.com/OpenCTI-Platform/opencti/releases/tag/7.260706.0
https://github.com/OpenCTI-Platform/opencti/security/advisories/GHSA-7g3x-wc2m-9h9x

Track CVE-2026-76821 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

7.5CVE-2026-28318SolarWinds Serv-U unauthenticated POST request denial of serviceSolarWinds Serv-U crashes when it receives a specially crafted POST request using Content-Encoding: deflate, and the crash occurs without authenticat…KEVEPSS 1.9%analysed7.5CVE-2026-45498Microsoft Defender antimalware platform uncontrolled resource consumption DoSCVE-2026-45498 is a denial of service flaw in the Microsoft Defender antimalware platform, classified as uncontrolled resource consumption (CWE-400).…KEVEPSS 1.3%analysed7.5CVE-2023-44487HTTP/2 Rapid Reset stream cancellation denial of serviceThe HTTP/2 protocol permits a client to cancel many streams quickly, and the server's handling of those resets consumes disproportionate resources. T…KEVEPSS 100%analysed7.5CVE-2023-38180Microsoft .NET and Visual Studio uncontrolled resource consumption DoSCVE-2023-38180 is a denial-of-service flaw in Microsoft .NET, ASP.NET Core and Visual Studio 2022, classified as uncontrolled resource consumption (C…KEVEPSS 14%analysed5.9CVE-2004-1464Cisco IOS Telnet VTY resource exhaustion denial of serviceCisco IOS 12.2(15) and earlier fails to properly handle crafted TCP connections to the Telnet or reverse Telnet port, exhausting virtual terminal (VT…KEVEPSS 4.8%analysed10.0CVE-2021-44228Apache Log4j2 JNDI lookup remote code executionApache Log4j2 versions 2.0-beta9 through 2.15.0 (excluding 2.12.2, 2.12.3, and 2.3.1) do not protect against attacker-controlled LDAP and other JNDI …KEVEPSS 100%analysed8.6CVE-2020-3569Cisco IOS XR DVMRP IGMP packet handling memory exhaustionCisco IOS XR Software mishandles IGMP packets in its Distance Vector Multicast Routing Protocol (DVMRP) feature, allowing crafted traffic to crash th…KEVEPSS 3.3%analysed8.6CVE-2020-3566Cisco IOS XR DVMRP IGMP queue flaw causes memory exhaustionCisco IOS XR Software mishandles queue management for IGMP packets in its DVMRP feature, allowing uncontrolled memory consumption. An unauthenticated…KEVEPSS 3.7%analysed

Source: NIST National Vulnerability Database (record CVE-2026-76821), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.