CVE-2025-26621: high-severity vulnerability in OpenCTI-Platform opencti
OpenCTI vulnerable to Denial of Service through web hook
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.6epss 0.4%
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to version 6.5.2, any user with the capability manage customizations can edit webhook that will execute javascript code. This can be abused to cause a denial of service attack by prototype pollution, making the node js server running the OpenCTI frontend become unavailable. Version 6.5.2 fixes the issue.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:L/A:H
Affected products
OpenCTI-Platform · openctiRelated CVEs — OpenCTI-Platform opencti
In the same product, most dangerous first.
CVE-2026-27960CRITICALOpenCTI privilege escalation and unauthenticated access via default admin accountEPSS 7.1%CVE-2026-39980CRITICALOpenCTI affected by RCE via notifier templateEPSS 1.4%CVE-2025-24977CRITICALOpenCTI has remote code execution and sensitive secrets exposed through web hookEPSS 0.9%CVE-2024-45404HIGHOpenCTI's lack of Rate Limit lead to OTP brute forcingEPSS 0.6%CVE-2026-35211MEDIUMOpenCTI: Elasticsearch Painless Script Injection via GraphQL `script` filter operator allows authenticated user to exfiltrate data and cause DoSEPSS 0.5%CVE-2026-76821HIGHOpenCTI: User-Controlled ReDoS in JSON Ingestion MapperEPSS 0.5%