{"cve":"CVE-2021-3859","nvd":{"published":"2022-08-26T16:15:09.623","modified":"2026-06-17T04:05:54.580","status":"Modified","description":"A flaw was found in Undertow that tripped the client-side invocation timeout with certain calls made over HTTP2. This flaw allows an attacker to carry out denial of service attacks.","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-214","CWE-668"],"references":["https://access.redhat.com/security/cve/CVE-2021-3859","https://bugzilla.redhat.com/show_bug.cgi?id=2010378","https://github.com/undertow-io/undertow/commit/e43f0ada3f4da6e8579e0020cec3cb1a81e487c2","https://github.com/undertow-io/undertow/pull/1296","https://issues.redhat.com/browse/UNDERTOW-1979"],"products":["netapp:cloud_secure_agent","netapp:oncommand_insight","netapp:oncommand_workflow_automation","redhat:jboss_enterprise_application_platform","redhat:single_sign-on","redhat:undertow"],"source":"nvd","synced_at":"2026-10-19T21:35:14.992143698+00:00"},"epss":{"cve":"CVE-2021-3859","score":0.01736,"percentile":0.77684,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-339q-62wm-c39w","url":"https://osv.dev/vulnerability/GHSA-339q-62wm-c39w","summary":"Undertow vulnerable to Denial of Service (DoS) attacks","modified":"2024-02-22T05:34:10.798768Z","packages":[{"ecosystem":"Maven","name":"io.undertow:undertow-core","purl":"pkg:maven/io.undertow/undertow-core","ranges":["<2.2.15"],"fixed":["2.2.15"]}]}],"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."]}