{"cve":{"cve_id":"CVE-2021-32640","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.02936,"epss_percentile":0.85308,"epss_as_of":"2026-06-23","description":"ws is an open source WebSocket client and server library for Node.js. A specially crafted value of the `Sec-Websocket-Protocol` header can be used to significantly slow down a ws server. The vulnerability has been fixed in ws@7.4.6 (https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff). In vulnerable versions of ws, the issue can be mitigated by reducing the maximum allowed length of the request headers using the [`--max-http-header-size=size`](https://nodejs.org/api/cli.html#cli_max_http_header_size_size) and/or the [`maxHeaderSize`](https://nodejs.org/api/http.html#http_http_createserver_options_requestlistener) options.","published_at":"2021-05-25T18:25:09Z","last_modified_at":null,"cvss_v3_score":5.3,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","cvss_v3_severity":"MEDIUM","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-400"],"nvd_references":["https://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693","https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff","https://lists.apache.org/thread.html/rdfa7b6253c4d6271e31566ecd5f30b7ce1b8fb2c89d52b8c4e0f4e30%40%3Ccommits.tinkerpop.apache.org%3E","https://security.netapp.com/advisory/ntap-20210706-0005/"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-28T23:15:39.534678Z"},"effective_severity":"MEDIUM","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"N","value_label":"None"},{"metric":"I","name":"Integrity","value":"N","value_label":"None"},{"metric":"A","name":"Availability","value":"L","value_label":"Low"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"websockets","vendor_name":"websockets","product_slug":"ws","product_name":"ws","version_start":">= 5.0.0 <= 7.4.5","version_start_inclusive":true,"version_end":">= 5.0.0 <= 7.4.5","version_end_inclusive":true,"cpe23_uri":"cve5:websockets:ws:>= 5.0.0 <= 7.4.5:>= 5.0.0 <= 7.4.5"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff","source_type":"PATCH","tags":["patch"]},{"url":"https://lists.apache.org/thread.html/rdfa7b6253c4d6271e31566ecd5f30b7ce1b8fb2c89d52b8c4e0f4e30%40%3Ccommits.tinkerpop.apache.org%3E","source_type":"MAILING_LIST","tags":["mailing-list","patch"]},{"url":"https://security.netapp.com/advisory/ntap-20210706-0005/","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2021-05-25T18:25:09Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:18:31.722192Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:18:31.722192Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:18:31.722192Z","label":"CVSS score revised","source":"cvelistv5"}]}