{"id":"CVE-2026-66752","aliases":["DEBIAN-CVE-2026-66752","EUVD-2026-49881","GHSA-5hc2-r3jq-vc45","UBUNTU-CVE-2026-66752"],"status":"published","title":"tiny-http 0.12.0 HTTP Request Smuggling via Transfer-Encoding Handling","description":"tiny-http through 0.12.0 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize request framing by sending a Transfer-Encoding header with any value, including non-chunked codings, which causes the library to unconditionally apply chunk-decoding and discard Content-Length. Attackers can exploit the discrepancy between tiny_http's improper Transfer-Encoding parsing and a correctly-implemented front-end proxy to produce two distinct interpretations of a single byte stream, enabling request smuggling, and can additionally send non-chunked bodies with non-chunked Transfer-Encoding values to cause failed body reads that tie up connections and consume worker threads without signaling errors to clients.","severity":{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00329,"percentile":0.262,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":false},"cwes":["CWE-444"],"published":"2026-07-28T15:44:41Z","modified":"2026-10-28T02:30:48Z","exploits":[{"source":"pocgithub","id":"theopaid/CVE-2026-66752-HTTP-Request-Smuggling-via-Unparsed-Transfer-Encoding-Values-tiny_http-","title":"theopaid/CVE-2026-66752-HTTP-Request-Smuggling-via-Unparsed-Transfer-Encoding-Values-tiny_http-","date":"2026-07-26","url":"https://github.com/theopaid/CVE-2026-66752-HTTP-Request-Smuggling-via-Unparsed-Transfer-Encoding-Values-tiny_http-"}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"rust-tiny-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.12.0-1"]},{"source":"osv","ecosystem":"Debian:13","package":"rust-tiny-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.12.0-1"]},{"source":"osv","ecosystem":"Debian:14","package":"rust-tiny-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.12.0-1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"rust-tiny-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.12.0-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"rust-tiny-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.12.0-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"rust-tiny-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.12.0-1"]}],"products":[{"vendor":"tiny-http","product":"tiny-http"}],"references":[{"url":"https://github.com/theopaid/HTTP-Request-Smuggling-via-Unparsed-Transfer-Encoding-Values-tiny_http-/tree/master","tags":["technical-description","exploit","evidence"]},{"url":"https://www.vulncheck.com/advisories/tiny-http-http-request-smuggling-via-transfer-encoding-handling","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66752","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-5hc2-r3jq-vc45"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66752.json","tags":["advisory"]},{"url":"https://github.com/tiny-http/tiny-http","tags":["package"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-66752","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-66752","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-66752","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-66752","title":"tiny-http 0.12.0 HTTP Request Smuggling via Transfer-Encoding Handling","description":"tiny-http through 0.12.0 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize request framing by sending a Transfer-Encoding header with any value, including non-chunked codings, which causes the library to unconditionally apply chunk-decoding and discard Content-Length. Attackers can exploit the discrepancy between tiny_http's improper Transfer-Encoding parsing and a correctly-implemented front-end proxy to produce two distinct interpretations of a single byte stream, enabling request smuggling, and can additionally send non-chunked bodies with non-chunked Transfer-Encoding values to cause failed body reads that tie up connections and consume worker threads without signaling errors to clients.","status":"published","published":"2026-07-28T15:44:41.573Z","modified":"2026-08-14T16:50:45.981Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L","level":"medium","assessor":"cna"},{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T14:20:13.272106Z"}],"euvd":[{"id":"EUVD-2026-49881","description":"tiny-http through 0.12.0 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize request framing by sending a Transfer-Encoding header with any value, including non-chunked codings, which causes the library to unconditionally apply chunk-decoding and discard Content-Length. Attackers can exploit the discrepancy between tiny_http's improper Transfer-Encoding parsing and a correctly-implemented front-end proxy to produce two distinct interpretations of a single byte stream, enabling request smuggling, and can additionally send non-chunked bodies with non-chunked Transfer-Encoding values to cause failed body reads that tie up connections and consume worker threads without signaling errors to clients.","status":"published","published":"2026-07-28T15:44:41Z","modified":"2026-08-14T16:50:45Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L","level":"medium"}],"updated_at":"2026-11-02T18:01:54.232317Z"}],"ghsa":[{"id":"GHSA-5hc2-r3jq-vc45","title":"tiny-http through 0.12.0 contains an HTTP request smuggling vulnerability that allows remote...","description":"tiny-http through 0.12.0 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize request framing by sending a Transfer-Encoding header with any value, including non-chunked codings, which causes the library to unconditionally apply chunk-decoding and discard Content-Length. Attackers can exploit the discrepancy between tiny_http's improper Transfer-Encoding parsing and a correctly-implemented front-end proxy to produce two distinct interpretations of a single byte stream, enabling request smuggling, and can additionally send non-chunked bodies with non-chunked Transfer-Encoding values to cause failed body reads that tie up connections and consume worker threads without signaling errors to clients.","status":"published","published":"2026-07-28T18:33:03Z","modified":"2026-07-28T18:33:05Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium"},{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T15:09:52.627235Z"}],"nvd":[{"id":"CVE-2026-66752","description":"tiny-http through 0.12.0 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize request framing by sending a Transfer-Encoding header with any value, including non-chunked codings, which causes the library to unconditionally apply chunk-decoding and discard Content-Length. Attackers can exploit the discrepancy between tiny_http's improper Transfer-Encoding parsing and a correctly-implemented front-end proxy to produce two distinct interpretations of a single byte stream, enabling request smuggling, and can additionally send non-chunked bodies with non-chunked Transfer-Encoding values to cause failed body reads that tie up connections and consume worker threads without signaling errors to clients.","status":"published","published":"2026-07-28T16:20:16.887Z","modified":"2026-07-30T20:03:32.983Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T14:12:33.249634Z"}],"osv":[{"id":"CVE-2026-66752","title":"tiny-http 0.12.0 HTTP Request Smuggling via Transfer-Encoding Handling","description":"tiny-http through 0.12.0 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize request framing by sending a Transfer-Encoding header with any value, including non-chunked codings, which causes the library to unconditionally apply chunk-decoding and discard Content-Length. Attackers can exploit the discrepancy between tiny_http's improper Transfer-Encoding parsing and a correctly-implemented front-end proxy to produce two distinct interpretations of a single byte stream, enabling request smuggling, and can additionally send non-chunked bodies with non-chunked Transfer-Encoding values to cause failed body reads that tie up connections and consume worker threads without signaling errors to clients.","status":"published","published":"2026-07-28T15:44:41.573Z","modified":"2026-10-28T02:30:48.217220021Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L","level":"medium"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T15:45:14.46177Z"},{"id":"DEBIAN-CVE-2026-66752","description":"tiny-http through 0.12.0 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize request framing by sending a Transfer-Encoding header with any value, including non-chunked codings, which causes the library to unconditionally apply chunk-decoding and discard Content-Length. Attackers can exploit the discrepancy between tiny_http's improper Transfer-Encoding parsing and a correctly-implemented front-end proxy to produce two distinct interpretations of a single byte stream, enabling request smuggling, and can additionally send non-chunked bodies with non-chunked Transfer-Encoding values to cause failed body reads that tie up connections and consume worker threads without signaling errors to clients.","status":"published","published":"2026-07-28T16:20:16.887Z","modified":"2026-10-01T03:03:38.693473448Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium"}],"updated_at":"2026-11-02T15:45:58.699079Z"},{"id":"UBUNTU-CVE-2026-66752","description":"tiny-http through 0.12.0 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize request framing by sending a Transfer-Encoding header with any value, including non-chunked codings, which causes the library to unconditionally apply chunk-decoding and discard Content-Length. Attackers can exploit the discrepancy between tiny_http's improper Transfer-Encoding parsing and a correctly-implemented front-end proxy to produce two distinct interpretations of a single byte stream, enabling request smuggling, and can additionally send non-chunked bodies with non-chunked Transfer-Encoding values to cause failed body reads that tie up connections and consume worker threads without signaling errors to clients.","status":"published","published":"2026-07-28T16:20:00Z","modified":"2026-10-17T12:56:41.705619634Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"medium"},{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L","level":"medium"}],"updated_at":"2026-11-02T16:56:53.710209Z"}]}}