{"apiVersion":"1.0","identifier":"CVE-2026-73256","description":"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.","publishedAt":"2026-08-20T18:16:46","lastModifiedAt":"2026-08-21T22:16:44","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-73256","cvssScore":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","epssProbability":0.00397,"riskScore":0.94,"affectedProduct":"Mongoose","affectedVersions":"<7.22","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-73256","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-73256","en":"https://www.redsauce.net/en/cves/CVE-2026-73256","fr":"https://www.redsauce.net/fr/cves/CVE-2026-73256","pt":"https://www.redsauce.net/pt/cves/CVE-2026-73256","de":"https://www.redsauce.net/de/cves/CVE-2026-73256","sk":"https://www.redsauce.net/sk/cves/CVE-2026-73256","el":"https://www.redsauce.net/el/cves/CVE-2026-73256"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-73256"}}