{"id":"CVE-2026-48743","aliases":["BIT-envoy-2026-48743","EUVD-2026-39822","GHSA-8phg-2h2q-jgxf","openSUSE-SU-2026:11141-1"],"status":"published","title":"Envoy: HTTP/3 to HTTP/1 request smuggling via headers-only request with nonzero Content-Length","description":"Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN / headers-only close) but still carries a nonzero Content-Length into a complete upstream HTTP/1 request with unresolved body debt. In an HTTP/1 upstream deployment where the origin replies before reading the declared body and keeps the connection reusable, the beginning of the next Envoy-generated upstream request can be consumed as the first request's body. The remaining bytes are then parsed by the origin as a new HTTP/1 request. This was reproduced as a route-bypass/desync: direct /pwn was denied by Envoy, but the second downstream H3 stream received the response for backend-parsed GET /pwn HTTP/1.1. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00298,"percentile":0.22717,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-444"],"published":"2026-06-26T17:34:22Z","modified":"2026-10-28T02:30:25Z","fixes":[{"ecosystem":"Bitnami","package":"envoy","fixed_in":["1.35.11","1.36.7","1.37.3","1.38.1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Bitnami","package":"envoy","ranges":[{"type":"SEMVER","events":[{"introduced":"1.35.0"},{"fixed":"1.35.11"},{"introduced":"1.36.0"},{"fixed":"1.36.7"},{"introduced":"1.37.0"},{"fixed":"1.37.3"},{"introduced":"1.38.0"},{"fixed":"1.38.1"}]}]},{"source":"osv","ecosystem":"openSUSE:Tumbleweed","package":"istioctl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.30.2-1.1"}]}],"bundled":14}],"products":[{"vendor":"envoyproxy","product":"envoy"}],"references":[{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-8phg-2h2q-jgxf","tags":["x_refsource_CONFIRM","exploit","Exploit","Vendor Advisory","Mitigation","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48743","tags":["web","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48743.json","tags":["advisory"]},{"url":"","tags":["advisory"]},{"url":"https://www.suse.com/security/cve/CVE-2026-47204","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-47205","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-47207","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-47220","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-47221","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-47692","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-47775","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-47778","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-48042","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-48044","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-48090","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-48497","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-48706","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-48743","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2026-48743","title":"Envoy: HTTP/3 to HTTP/1 request smuggling via headers-only request with nonzero Content-Length","description":"Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN / headers-only close) but still carries a nonzero Content-Length into a complete upstream HTTP/1 request with unresolved body debt. In an HTTP/1 upstream deployment where the origin replies before reading the declared body and keeps the connection reusable, the beginning of the next Envoy-generated upstream request can be consumed as the first request's body. The remaining bytes are then parsed by the origin as a new HTTP/1 request. This was reproduced as a route-bypass/desync: direct /pwn was denied by Envoy, but the second downstream H3 stream received the response for backend-parsed GET /pwn HTTP/1.1. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.","status":"published","published":"2026-06-26T17:34:22.47Z","modified":"2026-06-29T15:20:33.276Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T13:50:49.872037Z"}],"euvd":[{"id":"EUVD-2026-39822","description":"Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN / headers-only close) but still carries a nonzero Content-Length into a complete upstream HTTP/1 request with unresolved body debt. In an HTTP/1 upstream deployment where the origin replies before reading the declared body and keeps the connection reusable, the beginning of the next Envoy-generated upstream request can be consumed as the first request's body. The remaining bytes are then parsed by the origin as a new HTTP/1 request. This was reproduced as a route-bypass/desync: direct /pwn was denied by Envoy, but the second downstream H3 stream received the response for backend-parsed GET /pwn HTTP/1.1. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.","status":"published","published":"2026-06-26T17:34:22Z","modified":"2026-06-29T15:20:33Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T18:20:22.506413Z"}],"nvd":[{"id":"CVE-2026-48743","description":"Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN / headers-only close) but still carries a nonzero Content-Length into a complete upstream HTTP/1 request with unresolved body debt. In an HTTP/1 upstream deployment where the origin replies before reading the declared body and keeps the connection reusable, the beginning of the next Envoy-generated upstream request can be consumed as the first request's body. The remaining bytes are then parsed by the origin as a new HTTP/1 request. This was reproduced as a route-bypass/desync: direct /pwn was denied by Envoy, but the second downstream H3 stream received the response for backend-parsed GET /pwn HTTP/1.1. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.","status":"published","published":"2026-06-26T18:17:00.173Z","modified":"2026-10-25T17:10:00.197Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T14:12:26.045561Z"}],"osv":[{"id":"CVE-2026-48743","title":"Envoy: HTTP/3 to HTTP/1 request smuggling via headers-only request with nonzero Content-Length","description":"Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN / headers-only close) but still carries a nonzero Content-Length into a complete upstream HTTP/1 request with unresolved body debt. In an HTTP/1 upstream deployment where the origin replies before reading the declared body and keeps the connection reusable, the beginning of the next Envoy-generated upstream request can be consumed as the first request's body. The remaining bytes are then parsed by the origin as a new HTTP/1 request. This was reproduced as a route-bypass/desync: direct /pwn was denied by Envoy, but the second downstream H3 stream received the response for backend-parsed GET /pwn HTTP/1.1. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.","status":"published","published":"2026-06-26T17:34:22.47Z","modified":"2026-10-28T02:30:25.680511306Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N","level":"high"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T15:45:06.701612Z"},{"id":"BIT-envoy-2026-48743","title":"Envoy: HTTP/3 to HTTP/1 request smuggling via headers-only request with nonzero Content-Length","description":"Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN / headers-only close) but still carries a nonzero Content-Length into a complete upstream HTTP/1 request with unresolved body debt. In an HTTP/1 upstream deployment where the origin replies before reading the declared body and keeps the connection reusable, the beginning of the next Envoy-generated upstream request can be consumed as the first request's body. The remaining bytes are then parsed by the origin as a new HTTP/1 request. This was reproduced as a route-bypass/desync: direct /pwn was denied by Envoy, but the second downstream H3 stream received the response for backend-parsed GET /pwn HTTP/1.1. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.","status":"published","published":"2026-06-30T23:39:39.412Z","modified":"2026-09-08T08:47:28.69415339Z","updated_at":"2026-11-02T15:28:29.563843Z"},{"id":"openSUSE-SU-2026:11141-1","title":"istioctl-1.30.2-1.1 on GA media","description":"These are all security issues fixed in the istioctl-1.30.2-1.1 package on the GA media of openSUSE Tumbleweed.","status":"published","published":"2026-06-28T00:00:00Z","modified":"2026-06-29T09:45:08.482872076Z","updated_at":"2026-11-02T16:58:38.95195Z"}]}}