CVE-2026-48743
- Source
- https://cve.org/CVERecord?id=CVE-2026-48743
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48743.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-48743
- Aliases
-
- BIT-envoy-2026-48743
- GHSA-8phg-2h2q-jgxf
- Downstream
- Related
- Published
- 2026-06-26T17:34:22.470Z
- Modified
- 2026-07-08T08:26:26.159863705Z
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N CVSS Calculator
- Summary
- Envoy: HTTP/3 to HTTP/1 request smuggling via headers-only request with nonzero Content-Length
- Details
-
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.
- Database specific
{ "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48743.json", "cwe_ids": [ "CWE-444" ], "cna_assigner": "GitHub_M" }- References
Affected packages
Git / github.com/envoyproxy/envoy
Affected ranges
- Type
- GIT
- Repo
- https://github.com/envoyproxy/envoy
- Events
-
IntroducedFixedIntroducedFixedIntroducedFixedIntroducedFixed
- Database specific
{ "source": "CPE_RANGE", "cpe": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "extracted_events": [ { "introduced": "1.35.0" }, { "fixed": "1.35.13" }, { "introduced": "1.36.0" }, { "fixed": "1.36.9" }, { "introduced": "1.37.0" }, { "fixed": "1.37.5" }, { "introduced": "1.38.0" }, { "fixed": "1.38.3" } ] }