{"containers":{"cna":{"affected":[{"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","modules":["'Elixir.Bandit.Headers'"],"packageName":"bandit","packageURL":"pkg:hex/bandit","product":"bandit","programFiles":["lib/bandit/headers.ex"],"programRoutines":[{"name":"'Elixir.Bandit.Headers':get_content_length/1"}],"repo":"https://github.com/mtrudel/bandit","vendor":"mtrudel","versions":[{"lessThan":"1.11.0","status":"affected","version":"0","versionType":"semver"}]},{"collectionURL":"https://github.com","cpes":["cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","modules":["'Elixir.Bandit.Headers'"],"packageName":"mtrudel/bandit","packageURL":"pkg:github/mtrudel/bandit","product":"bandit","programFiles":["lib/bandit/headers.ex"],"programRoutines":[{"name":"'Elixir.Bandit.Headers':get_content_length/1"}],"repo":"https://github.com/mtrudel/bandit","vendor":"mtrudel","versions":[{"lessThan":"1.11.0","status":"affected","version":"0","versionType":"git"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*","versionEndExcluding":"1.11.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"Peter Ullrich"},{"lang":"en","type":"remediation developer","value":"Mat Trudel"},{"lang":"en","type":"analyst","value":"Jonatan Männchen"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Inconsistent Interpretation of HTTP Requests vulnerability in mtrudel bandit allows HTTP request smuggling via duplicate <tt>Content-Length</tt> headers.<p><tt>'Elixir.Bandit.Headers':get_content_length/1</tt> in <tt>lib/bandit/headers.ex</tt> uses <tt>List.keyfind/3</tt>, which returns only the first matching header. When a request contains two <tt>Content-Length</tt> headers with different values, Bandit silently accepts it, uses the first value to read the body, and dispatches the remaining bytes as a second pipelined request on the same keep-alive connection. RFC 9112 §6.3 requires recipients to treat this as an unrecoverable framing error.</p><p>When Bandit sits behind a proxy that picks the last <tt>Content-Length</tt> value and forwards the request rather than rejecting it, an unauthenticated attacker can smuggle requests past edge WAF rules, path-based ACLs, rate limiting, and audit logging.</p><p>This issue affects bandit: before 1.11.0.</p>"}],"value":"Inconsistent Interpretation of HTTP Requests vulnerability in mtrudel bandit allows HTTP request smuggling via duplicate Content-Length headers.\n\n'Elixir.Bandit.Headers':get_content_length/1 in lib/bandit/headers.ex uses List.keyfind/3, which returns only the first matching header. When a request contains two Content-Length headers with different values, Bandit silently accepts it, uses the first value to read the body, and dispatches the remaining bytes as a second pipelined request on the same keep-alive connection. RFC 9112 §6.3 requires recipients to treat this as an unrecoverable framing error.\n\nWhen Bandit sits behind a proxy that picks the last Content-Length value and forwards the request rather than rejecting it, an unauthenticated attacker can smuggle requests past edge WAF rules, path-based ACLs, rate limiting, and audit logging.\n\nThis issue affects bandit: before 1.11.0."}],"impacts":[{"capecId":"CAPEC-33","descriptions":[{"lang":"en","value":"CAPEC-33 HTTP Request Smuggling"}]}],"metrics":[{"cvssV4_0":{"attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":6.3,"baseSeverity":"MEDIUM","privilegesRequired":"NONE","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-444","description":"CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-05-01T20:34:29.400Z","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","shortName":"EEF"},"references":[{"tags":["vendor-advisory","related"],"url":"https://github.com/mtrudel/bandit/security/advisories/GHSA-c67r-gc9j-2qf7"},{"tags":["related"],"url":"https://cna.erlef.org/cves/CVE-2026-39805.html"},{"tags":["related"],"url":"https://osv.dev/vulnerability/EEF-CVE-2026-39805"},{"tags":["patch"],"url":"https://github.com/mtrudel/bandit/commit/f2ca636eb6df385219957e8934e9fc6efa1630d1"}],"source":{"discovery":"EXTERNAL"},"title":"CL.CL HTTP request smuggling via duplicate Content-Length in bandit","x_generator":{"engine":"cvelib 1.8.0"}}},"cveMetadata":{"assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","assignerShortName":"EEF","cveId":"CVE-2026-39805","datePublished":"2026-05-01T20:34:29.400Z","dateReserved":"2026-04-07T12:28:54.916Z","dateUpdated":"2026-05-01T20:34:29.400Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"}