{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-73256","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-08-11T17:18:01.598Z","datePublished":"2026-08-20T17:37:54.505Z","dateUpdated":"2026-08-21T21:46:47.832Z"},"containers":{"cna":{"title":"Mongoose: HTTP/1.0 detection off-by-one enables request smuggling via chunked TE","problemTypes":[{"descriptions":[{"cweId":"CWE-444","lang":"en","description":"CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":9.1,"baseSeverity":"CRITICAL","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/cesanta/mongoose/security/advisories/GHSA-mgp5-rjrv-h5j3","tags":["x_refsource_CONFIRM"],"url":"https://github.com/cesanta/mongoose/security/advisories/GHSA-mgp5-rjrv-h5j3"},{"name":"https://github.com/cesanta/mongoose/pull/3611","tags":["x_refsource_MISC"],"url":"https://github.com/cesanta/mongoose/pull/3611"},{"name":"https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71","tags":["x_refsource_MISC"],"url":"https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71"},{"name":"https://github.com/cesanta/mongoose/releases/tag/7.22","tags":["x_refsource_MISC"],"url":"https://github.com/cesanta/mongoose/releases/tag/7.22"}],"affected":[{"vendor":"cesanta","product":"mongoose","versions":[{"version":"< 7.22","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-08-20T17:37:54.505Z"},"descriptions":[{"lang":"en","value":"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."}],"source":{"advisory":"GHSA-mgp5-rjrv-h5j3","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-21T21:10:40.015064Z","id":"CVE-2026-73256","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-21T21:46:47.832Z"}}]}}