{"id":"CVE-2026-48861","state":"PUBLISHED","title":"CRLF injection in HTTP/1 request line via unvalidated method in Mint","description":"Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in elixir-mint Mint allows HTTP Request Splitting and HTTP Request Smuggling.\n\nIn lib/mint/http1/request.ex, the encode_request_line/2 function splices the caller-supplied method and target arguments directly into the HTTP/1 request line without any character validation: [method, ?\\s, target, \" HTTP/1.1\\r\\n\"]. An application that forwards attacker-controlled input as the HTTP method or target to Mint.HTTP.request/5 is therefore exposed to request-line CRLF injection: the attacker can terminate the request line early, inject arbitrary headers, and smuggle an entirely separate pipelined HTTP request onto the same TCP connection.\n\nMint 1.7.0 introduced validate_request_target/2, which rejects CRLF and other control characters in the target by default and closes the path/query vector unless the caller opts out via skip_target_validation: true. The method field remains unvalidated, so the method-based injection is exploitable under the default Mint configuration on all versions.\n\nThis issue affects mint: from 0.1.0 before 1.9.0.","publishedAt":"2026-06-02T14:15:09.015Z","updatedAt":"2026-06-02T19:14:00.466Z","severity":{"score":2.1,"label":"Low","version":"4.0","vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N","source":"EEF"},"assigner":"EEF","products":["elixir-mint mint"],"affected":[{"vendor":"elixir-mint","product":"mint","packageName":"mint","packageURL":"pkg:hex/mint","defaultStatus":"unaffected","versions":[{"version":"0.1.0","status":"affected","lessThan":"1.9.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Mint.HTTP1.Request'"],"programFiles":["lib/mint/http1/request.ex"],"programRoutines":[{"name":"'Elixir.Mint.HTTP1.Request':encode_request_line/2"}],"repo":"https://github.com/elixir-mint/mint"},{"vendor":"elixir-mint","product":"mint","packageName":"elixir-mint/mint","packageURL":"pkg:github/elixir-mint/mint","defaultStatus":"unaffected","versions":[{"version":"8db1acff30b6a9433762c18b1e1f891b8c1f74f7","status":"affected","lessThan":"fad091454cbb7449b19edb8e1fee12ca7cf28c3a","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Mint.HTTP1.Request'"],"programFiles":["lib/mint/http1/request.ex"],"programRoutines":[{"name":"'Elixir.Mint.HTTP1.Request':encode_request_line/2"}],"repo":"https://github.com/elixir-mint/mint.git"}],"references":["https://github.com/elixir-mint/mint/security/advisories/GHSA-2pg6-44cx-c49v","https://cna.erlef.org/cves/CVE-2026-48861.html","https://osv.dev/vulnerability/EEF-CVE-2026-48861","https://github.com/elixir-mint/mint/commit/fad091454cbb7449b19edb8e1fee12ca7cf28c3a"],"weaknesses":["CWE-93"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/48xxx/CVE-2026-48861.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-48861","state":"PUBLISHED","datePublished":"2026-06-02T14:15:09.015Z","dateUpdated":"2026-06-02T19:14:00.466Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-05-25T20:44:10.697Z"},"containers":{"cna":{"title":"CRLF injection in HTTP/1 request line via unvalidated method in Mint","descriptions":[{"lang":"en","value":"Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in elixir-mint Mint allows HTTP Request Splitting and HTTP Request Smuggling.\n\nIn lib/mint/http1/request.ex, the encode_request_line/2 function splices the caller-supplied method and target arguments directly into the HTTP/1 request line without any character validation: [method, ?\\s, target, \" HTTP/1.1\\r\\n\"]. An application that forwards attacker-controlled input as the HTTP method or target to Mint.HTTP.request/5 is therefore exposed to request-line CRLF injection: the attacker can terminate the request line early, inject arbitrary headers, and smuggle an entirely separate pipelined HTTP request onto the same TCP connection.\n\nMint 1.7.0 introduced validate_request_target/2, which rejects CRLF and other control characters in the target by default and closes the path/query vector unless the caller opts out via skip_target_validation: true. The method field remains unvalidated, so the method-based injection is exploitable under the default Mint configuration on all versions.\n\nThis issue affects mint: from 0.1.0 before 1.9.0."}],"affected":[{"vendor":"elixir-mint","product":"mint","packageName":"mint","packageURL":"pkg:hex/mint","defaultStatus":"unaffected","versions":[{"version":"0.1.0","status":"affected","lessThan":"1.9.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Mint.HTTP1.Request'"],"programFiles":["lib/mint/http1/request.ex"],"programRoutines":[{"name":"'Elixir.Mint.HTTP1.Request':encode_request_line/2"}],"repo":"https://github.com/elixir-mint/mint"},{"vendor":"elixir-mint","product":"mint","packageName":"elixir-mint/mint","packageURL":"pkg:github/elixir-mint/mint","defaultStatus":"unaffected","versions":[{"version":"8db1acff30b6a9433762c18b1e1f891b8c1f74f7","status":"affected","lessThan":"fad091454cbb7449b19edb8e1fee12ca7cf28c3a","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Mint.HTTP1.Request'"],"programFiles":["lib/mint/http1/request.ex"],"programRoutines":[{"name":"'Elixir.Mint.HTTP1.Request':encode_request_line/2"}],"repo":"https://github.com/elixir-mint/mint.git"}],"references":[{"url":"https://github.com/elixir-mint/mint/security/advisories/GHSA-2pg6-44cx-c49v","tags":["vendor-advisory","related"]},{"url":"https://cna.erlef.org/cves/CVE-2026-48861.html","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-48861","tags":["related"]},{"url":"https://github.com/elixir-mint/mint/commit/fad091454cbb7449b19edb8e1fee12ca7cf28c3a","tags":["patch"]}],"metrics":[{"cvssV4_0":{"attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"LOCAL","baseScore":2.1,"baseSeverity":"LOW","privilegesRequired":"NONE","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"LOW","userInteraction":"NONE","vectorString":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-93","description":"CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"EEF","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateUpdated":"2026-06-02T19:14:00.466Z"},"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:*","versionEndExcluding":"1.9.0","versionStartIncluding":"0.1.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"Peter Ullrich"},{"lang":"en","type":"remediation developer","value":"Eric Meadows-Jönsson"},{"lang":"en","type":"analyst","value":"Jonatan Männchen / EEF"}],"impacts":[{"capecId":"CAPEC-33","descriptions":[{"lang":"en","value":"CAPEC-33 HTTP Request Smuggling"}]},{"capecId":"CAPEC-105","descriptions":[{"lang":"en","value":"CAPEC-105 HTTP Request Splitting"}]}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/elixir-mint/mint/security/advisories/GHSA-2pg6-44cx-c49v","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-02T18:11:46.297986Z","id":"CVE-2026-48861","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-02T18:12:22.736Z"}}]}}}