{"id":"GHSA-mp55-p8c9-rfw2","summary":"Hackney has CRLF / header injection via unvalidated `domain` and `path` options","details":"### Summary\n\nCRLF injection in `hackney_cookie:setcookie/3` (`src/hackney_cookie.erl`). The function validates `Name` and `Value` against CR/LF and control characters but concatenates the `domain` and `path` options verbatim into the output binary. If either option carries attacker-controlled data, a `Host` header forwarded as the cookie domain, a request URI forwarded as the cookie path, a `\\r\\n` in the value splits the `Set-Cookie` header and lets the attacker inject additional headers into the HTTP response.\n\n### Details\n\n**1. Asymmetric validation**\n\nLines 27–34 of `hackney_cookie.erl` run `binary:match` on `Name` and `Value`, rejecting `=`, `,`, `;`, whitespace, `\\r`, `\\n`, `\\013`, and `\\014`. The `Domain` and `Path` options (lines 47 and 51) skip this check entirely and land straight in the result iolist:\n\n```erlang\n[\u003c\u003c\"; Domain=\"\u003e\u003e, Domain]\n[\u003c\u003c\"; Path=\"\u003e\u003e,   Path]\n```\n\n`iolist_to_binary(...)` on line 63 flattens everything and returns it to the caller.\n\n**2. Injection**\n\nA `Path` of `\u003c\u003c\"/x\\r\\nSet-Cookie: admin=1; Path=/\"\u003e\u003e` produces a binary with a literal `\\r\\n`. Written into a `Set-Cookie` response header, the receiving HTTP parser splits it into two headers — one legitimate, one attacker-controlled.\n\n**3. Realistic trigger**\n\nCommon patterns: keying the cookie domain off `Host`, deriving the path from the request URI, or copying a `Location` path into a cookie. Any of these lets a remote attacker control the injected content.\n\n### PoC\n\n1. Call `hackney_cookie:setcookie(\u003c\u003c\"sid\"\u003e\u003e, \u003c\u003c\"abc\"\u003e\u003e, [{path, \u003c\u003c\"/x\\r\\nSet-Cookie: admin=1; Path=/\"\u003e\u003e}])`.\n2. The returned binary contains a literal `\\r\\n` followed by a second `Set-Cookie:` line.\n3. Write the result into a `Set-Cookie` response header — the client parses two headers, including `admin=1`.\n\n### Impact\n\nCookie injection / HTTP response splitting at the `hackney_cookie` API boundary. Affects hackney 0.9.0 through 4.0.0 wherever `domain` or `path` options are populated from request data. Exploitation can overwrite session/auth cookies, fix cookies, or strip `Secure`/`HttpOnly` flags. CVSS v4.0: **2.1 (LOW)** — requires attacker-controlled input to reach the `domain` or `path` option.\n\n## Resources\n\n* Introduction commit: https://github.com/benoitc/hackney/commit/602d5c7f2ea4acbc83ed75230655d935a0750ebc\n* Patch commit: https://github.com/benoitc/hackney/commit/8e02b99c28aea1b3fa2ddc0e66f51fe5bb0ac540","aliases":["CVE-2026-47069","EEF-CVE-2026-47069"],"modified":"2026-06-26T22:00:10.691062066Z","published":"2026-06-26T21:54:19Z","database_specific":{"cwe_ids":["CWE-93"],"severity":"LOW","github_reviewed":true,"github_reviewed_at":"2026-06-26T21:54:19Z","nvd_published_at":"2026-05-25T15:16:21Z"},"references":[{"type":"WEB","url":"https://github.com/benoitc/hackney/security/advisories/GHSA-mp55-p8c9-rfw2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-47069"},{"type":"WEB","url":"https://github.com/benoitc/hackney/commit/8e02b99c28aea1b3fa2ddc0e66f51fe5bb0ac540"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-47069.html"},{"type":"PACKAGE","url":"https://github.com/benoitc/hackney"},{"type":"WEB","url":"https://osv.dev/vulnerability/EEF-CVE-2026-47069"}],"affected":[{"package":{"name":"hackney","ecosystem":"Hex","purl":"pkg:hex/hackney"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.9.0"},{"fixed":"4.0.1"}]}],"versions":["0.13.1","0.14.0","0.14.1","0.14.2","0.14.3","0.15.0","0.15.2","1.0.1","1.0.2","1.0.5","1.0.6","1.1.0","1.10.0","1.10.1","1.11.0","1.12.0","1.12.1","1.13.0","1.14.0","1.14.2","1.14.3","1.15.0","1.15.1","1.15.2","1.16.0","1.17.0","1.17.1","1.17.2","1.17.3","1.17.4","1.18.0","1.18.1","1.18.2","1.19.0","1.19.1","1.2.0","1.20.0","1.20.1","1.21.0","1.22.0","1.23.0","1.24.0","1.24.1","1.25.0","1.3.0","1.3.1","1.3.2","1.4.0","1.4.1","1.4.10","1.4.2","1.4.3","1.4.4","1.4.5","1.4.6","1.4.7","1.4.8","1.5.0","1.5.1","1.5.2","1.5.3","1.5.4","1.5.5","1.5.6","1.5.7","1.6.0","1.6.1","1.6.2","1.6.3","1.6.4","1.6.5","1.6.6","1.7.0","1.7.1","1.8.0","1.8.2","1.8.3","1.8.4","1.8.5","1.8.6","1.9.0","2.0.0","2.0.0-beta.1","2.0.1","3.0.0","3.0.1","3.0.2","3.0.3","3.1.0","3.1.1","3.1.2","3.2.0","3.2.1","4.0.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-mp55-p8c9-rfw2/GHSA-mp55-p8c9-rfw2.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}