{"id":"CVE-2020-7662","url":"https://www.cyber-defence.io/tools/cve/CVE-2020-7662","generatedAt":"2026-10-28T01:52:31.867Z","title":"websocket-extensions npm module prior to 0.1.4 allows Denial of Service (DoS) via Regex Backtracking.","description":"websocket-extensions npm module prior to 0.1.4 allows Denial of Service (DoS) via Regex Backtracking. The extension parser may take quadratic time when parsing a header containing an unclosed string parameter value whose content is a repeating two-byte sequence of a backslash and some other character. This could be abused by an attacker to conduct Regex Denial Of Service (ReDoS) on a single-threaded server by providing a malicious payload with the Sec-WebSocket-Extensions header.","published":"2020-06-02T19:15:12.000Z","lastModified":"2026-06-17T03:25:13.000Z","status":"Modified","sourceIdentifier":"report@snyk.io","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":[],"affected":["websocket-extensions project/websocket-extensions"],"epss":{"score":0.03088,"percentile":0.8762,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (3.09%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://blog.jcoglan.com/2020/06/02/redos-vulnerability-in-websocket-extensions","tags":["Exploit","Third Party Advisory"],"source":"report@snyk.io"},{"url":"https://github.com/faye/websocket-extensions-node/commit/29496f6838bfadfe5a2f85dff33ed0ba33873237","tags":["Patch","Third Party Advisory"],"source":"report@snyk.io"},{"url":"https://github.com/faye/websocket-extensions-node/security/advisories/GHSA-g78m-2chm-r7qv","tags":["Exploit","Third Party Advisory"],"source":"report@snyk.io"},{"url":"https://snyk.io/vuln/SNYK-JS-WEBSOCKETEXTENSIONS-570623","tags":["Exploit","Technical Description","Third Party Advisory"],"source":"report@snyk.io"},{"url":"https://blog.jcoglan.com/2020/06/02/redos-vulnerability-in-websocket-extensions","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/faye/websocket-extensions-node/commit/29496f6838bfadfe5a2f85dff33ed0ba33873237","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/faye/websocket-extensions-node/security/advisories/GHSA-g78m-2chm-r7qv","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://snyk.io/vuln/SNYK-JS-WEBSOCKETEXTENSIONS-570623","tags":["Exploit","Technical Description","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2020-7662","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}