{"cve":"CVE-2020-1935","nvd":{"published":"2020-02-24T22:15:11.980","modified":"2026-10-08T21:17:24.610","status":"Modified","description":"In Apache Tomcat 9.0.0.M1 to 9.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99 the HTTP header parsing code used an approach to end-of-line parsing that allowed some invalid HTTP headers to be parsed as valid. This led to a possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. Such a reverse proxy is considered unlikely.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","score":4.8},"cwes":["CWE-444"],"references":["http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00025.html","https://lists.apache.org/thread.html/r127f76181aceffea2bd4711b03c595d0f115f63e020348fe925a916c%40%3Cannounce.tomcat.apache.org%3E","https://lists.apache.org/thread.html/r441c1f30a252bf14b07396286f6abd8089ce4240e91323211f1a2d75%40%3Cusers.tomcat.apache.org%3E","https://lists.apache.org/thread.html/r660cd379afe346f10d72c0eaa8459ccc95d83aff181671b7e9076919%40%3Cusers.tomcat.apache.org%3E","https://lists.apache.org/thread.html/r7bc994c965a34876bd94d5ff15b4e1e30b6220a15eb9b47c81915b78%40%3Ccommits.tomee.apache.org%3E"],"products":["apache:tomcat","canonical:ubuntu_linux","debian:debian_linux","netapp:data_availability_services","netapp:oncommand_system_manager","opensuse:leap","oracle:agile_engineering_data_management","oracle:agile_product_lifecycle_management","oracle:communications_element_manager","oracle:communications_instant_messaging_server","oracle:health_sciences_empirica_inspections","oracle:health_sciences_empirica_signal","oracle:hospitality_guest_access","oracle:hyperion_infrastructure_technology","oracle:instantis_enterprisetrack","oracle:mysql_enterprise_monitor","oracle:retail_order_broker","oracle:siebel_ui_framework","oracle:transportation_management","oracle:workload_manager"],"source":"nvd","synced_at":"2026-10-19T21:02:53.949909883+00:00"},"epss":{"cve":"CVE-2020-1935","score":0.09386,"percentile":0.95367,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-qxf4-chvg-4r8r","url":"https://osv.dev/vulnerability/GHSA-qxf4-chvg-4r8r","summary":"Potential HTTP request smuggling in Apache Tomcat","modified":"2026-08-07T08:12:22.137703329Z","packages":[{"ecosystem":"Maven","name":"org.apache.tomcat.embed:tomcat-embed-core","purl":"pkg:maven/org.apache.tomcat.embed/tomcat-embed-core","ranges":["<7.0.100"],"fixed":["7.0.100"]},{"ecosystem":"Maven","name":"org.apache.tomcat.embed:tomcat-embed-core","purl":"pkg:maven/org.apache.tomcat.embed/tomcat-embed-core","ranges":[">=8.0.0 <8.5.51"],"fixed":["8.5.51"]},{"ecosystem":"Maven","name":"org.apache.tomcat.embed:tomcat-embed-core","purl":"pkg:maven/org.apache.tomcat.embed/tomcat-embed-core","ranges":[">=9.0.0 <9.0.31"],"fixed":["9.0.31"]},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","purl":"pkg:maven/org.apache.tomcat/tomcat","ranges":["<7.0.100"],"fixed":["7.0.100"]},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","purl":"pkg:maven/org.apache.tomcat/tomcat","ranges":[">=8.0.0 <8.5.51"],"fixed":["8.5.51"]},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","purl":"pkg:maven/org.apache.tomcat/tomcat","ranges":[">=9.0.0 <9.0.31"],"fixed":["9.0.31"]}]}],"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."]}