{"cve":"CVE-2017-2666","nvd":{"published":"2018-07-27T14:29:00.207","modified":"2026-06-17T01:16:37.100","status":"Modified","description":"It was discovered in Undertow that the code that parsed the HTTP request line permitted invalid characters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a different interpretation, to inject data into the HTTP response. By manipulating the HTTP response the attacker could poison a web-cache, perform an XSS attack, or obtain sensitive information from requests other than their own.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","score":6.5},"cwes":["CWE-444"],"references":["http://rhn.redhat.com/errata/RHSA-2017-1409.html","http://www.securityfocus.com/bid/98966","https://access.redhat.com/errata/RHSA-2017:1410","https://access.redhat.com/errata/RHSA-2017:1411","https://access.redhat.com/errata/RHSA-2017:1412"],"products":["debian:debian_linux","redhat:jboss_enterprise_application_platform","redhat:undertow"],"source":"nvd","synced_at":"2026-10-19T20:52:03.425131697+00:00"},"epss":{"cve":"CVE-2017-2666","score":0.03095,"percentile":0.87735,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-mcfm-h73v-635m","url":"https://osv.dev/vulnerability/GHSA-mcfm-h73v-635m","summary":"Undertow-core vulnerable to HTTP Request Smuggling","modified":"2023-11-08T03:59:19.673972Z","packages":[{"ecosystem":"Maven","name":"io.undertow:undertow-core","purl":"pkg:maven/io.undertow/undertow-core","ranges":["<1.3.31"],"fixed":["1.3.31"]},{"ecosystem":"Maven","name":"io.undertow:undertow-core","purl":"pkg:maven/io.undertow/undertow-core","ranges":[">=1.4.0 <1.4.17"],"fixed":["1.4.17"]}]}],"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."]}