{"id":"JLSEC-2026-1380","details":"Mongoose is an embedded web server and network library. Prior to 7.22, a remote unauthenticated attacker can exploit an HTTP/1.0 reverse-proxy deployment by sending a request with Transfer-Encoding: chunked and conflicting framing. The `http_cb()` function in `src/http.c` tests hm.proto.len with an impossible greater-than-eight condition even though `mg_http_parse()` requires an eight-byte protocol string, so `is_http_1_0` is never set. Mongoose consequently processes chunked encoding that an HTTP/1.0 proxy can ignore, enabling request smuggling and unauthorized access or state changes. This issue is fixed in version 7.22.","modified":"2026-08-24T14:00:03.434021661Z","published":"2026-08-24T13:43:17.899Z","upstream":["CVE-2026-73256","EUVD-2026-63497"],"database_specific":{"sources":[{"id":"CVE-2026-73256","imported":"2026-08-23T06:21:07.087Z","modified":"2026-08-21T22:16:44.713Z","published":"2026-08-20T18:16:46.523Z","url":"https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-73256","html_url":"https://nvd.nist.gov/vuln/detail/CVE-2026-73256","database_specific":{"status":"Received"}},{"published":"2026-08-20T17:37:54Z","url":"https://euvdservices.enisa.europa.eu/api/enisaid?id=EUVD-2026-63497","html_url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-63497","affected":{"Cesanta:Mongoose":["\u003c 7.22"]},"id":"EUVD-2026-63497","imported":"2026-08-23T06:20:06.544Z","modified":"2026-08-21T21:46:47Z"}],"license":"CC-BY-4.0"},"references":[{"type":"WEB","url":"https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71"},{"type":"WEB","url":"https://github.com/cesanta/mongoose/pull/3611"},{"type":"WEB","url":"https://github.com/cesanta/mongoose/releases/tag/7.22"},{"type":"WEB","url":"https://github.com/cesanta/mongoose/security/advisories/GHSA-mgp5-rjrv-h5j3"}],"affected":[{"package":{"name":"Mongoose_jll","ecosystem":"Julia","purl":"pkg:julia/Mongoose_jll?uuid=0a8a3f5b-4c0e-5906-8e29-5b3fee15539c"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"}]}],"database_specific":{"source":"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1380.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","source":"CNA"}]}