{"cve":"CVE-2023-43622","nvd":{"published":"2023-10-23T07:15:11.243","modified":"2026-06-17T06:26:05.477","status":"Modified","description":"An attacker, opening a HTTP/2 connection with an initial window size of 0, was able to block handling of that connection indefinitely in Apache HTTP Server. This could be used to exhaust worker resources in the server, similar to the well known \"slow loris\" attack pattern.\nThis has been fixed in version 2.4.58, so that such connection are terminated properly after the configured connection timeout.\n\nThis issue affects Apache HTTP Server: from 2.4.55 through 2.4.57.\n\nUsers are recommended to upgrade to version 2.4.58, which fixes the issue.","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://httpd.apache.org/security/vulnerabilities_24.html","https://security.netapp.com/advisory/ntap-20231027-0011/","https://httpd.apache.org/security/vulnerabilities_24.html","https://security.netapp.com/advisory/ntap-20231027-0011/"],"products":["apache:http_server"],"source":"nvd","synced_at":"2026-10-19T21:40:11.519948003+00:00"},"epss":{"cve":"CVE-2023-43622","score":0.68818,"percentile":0.99346,"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."]}