{"cve":"CVE-2020-15166","nvd":{"published":"2020-09-11T16:15:12.177","modified":"2026-06-17T02:56:10.913","status":"Modified","description":"In ZeroMQ before version 4.3.3, there is a denial-of-service vulnerability. Users with TCP transport public endpoints, even with CURVE/ZAP enabled, are impacted. If a raw TCP socket is opened and connected to an endpoint that is fully configured with CURVE/ZAP, legitimate clients will not be able to exchange any message. Handshakes complete successfully, and messages are delivered to the library, but the server application never receives them. This is patched in version 4.3.3.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-400"],"references":["https://github.com/zeromq/libzmq/pull/3913","https://github.com/zeromq/libzmq/pull/3973","https://github.com/zeromq/libzmq/security/advisories/GHSA-25wp-cf8g-938m","https://lists.debian.org/debian-lts-announce/2020/11/msg00017.html","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BZ5IMNQXDB52JFBXHFLK4AHVORFELNNG/"],"products":["debian:debian_linux","fedoraproject:fedora","zeromq:libzmq"],"source":"nvd","synced_at":"2026-10-19T21:09:20.498348299+00:00"},"epss":{"cve":"CVE-2020-15166","score":0.03316,"percentile":0.88577,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}