CVE-2026-76821
Scheduled ingestion could repeatedly execute the malicious mapper without additional attacker action, and recovery could require disabling the mapper and restarting the process.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.47%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public 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.
- CVSS 4.0
- 7.1 HIGHCVSS: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/M
- EPSS
- 0.47% probability · 40th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-400, CWE-1333
- Source
- security-advisories@github.com
EPSS 0.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.