{"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"}}]}}

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