{"id":"CVE-2020-27782","aliases":["GHSA-rhcw-wjcm-9h6g"],"url":"https://o3.security/vulnerability/CVE-2020-27782","summary":"Denial of service in Undertow","details":"A flaw was found in the Undertow AJP connector. Malicious requests and abrupt connection closes could be triggered by an attacker using query strings with non-RFC compliant characters resulting in a denial of service. The highest threat from this vulnerability is to system availability. This affects Undertow 2.1.5.SP1, 2.0.33.SP2, and 2.2.3.SP1.","published":"2021-02-23T19:15:13.150Z","modified":"2026-03-14T10:07:02.052741Z","cvss":{"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"},"epss":{"score":0.01375,"percentile":0.69531,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"io.undertow:undertow-core","fixedVersion":"2.1.5"},{"ecosystem":"Maven","name":"io.undertow:undertow-core","fixedVersion":"2.0.33"}],"fix":{"url":"https://github.com/undertow-io/undertow/pull/997/commits/98a9ab7f2d7fe7a7254eaf17d47816c452169c90","label":"undertow-io/undertow#997"},"references":[{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=1901304"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-27782"},{"type":"WEB","url":"https://github.com/undertow-io/undertow/pull/997/commits/98a9ab7f2d7fe7a7254eaf17d47816c452169c90"},{"type":"WEB","url":"https://issues.redhat.com/browse/UNDERTOW-1813"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-03-14T10:07:02.052741Z"}}