eef-cve-2026-112880

{
  "affected": [
    {
      "database_specific": {
        "source": "https://cna.erlef.org/osv/EEF-CVE-2026-112880.json"
      },
      "package": {
        "ecosystem": "Hex",
        "name": "hackney",
        "purl": "pkg:hex/hackney"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0"
            },
            {
              "fixed": "4.9.0"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "versions": [
        "2.0.0",
        "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",
        "4.0.1",
        "4.0.2",
        "4.0.3",
        "4.1.0",
        "4.2.0",
        "4.2.1",
        "4.2.2",
        "4.2.3",
        "4.3.0",
        "4.4.0",
        "4.4.1",
        "4.4.2",
        "4.4.3",
        "4.4.5",
        "4.5.0",
        "4.5.1",
        "4.5.2",
        "4.6.0",
        "4.6.1",
        "4.7.0",
        "4.7.1",
        "4.7.2",
        "4.7.3",
        "4.7.4",
        "4.8.0",
        "4.8.1",
        "4.8.2",
        "4.8.3",
        "4.8.4",
        "4.8.5",
        "4.8.6",
        "4.8.7"
      ]
    },
    {
      "database_specific": {
        "source": "https://cna.erlef.org/osv/EEF-CVE-2026-112880.json"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5df5a74a2817d5b12880d217db33253ff1fae1b5"
            },
            {
              "fixed": "5ee7d7d19eba27e774667d472feb1e93a08af7f9"
            }
          ],
          "repo": "https://github.com/benoitc/hackney",
          "type": "GIT"
        }
      ],
      "versions": [
        "4.8.7",
        "4.8.6",
        "4.8.5",
        "4.8.4",
        "4.8.3",
        "4.8.2",
        "4.8.1",
        "4.8.0",
        "4.7.4",
        "4.7.3",
        "4.7.2",
        "4.7.1",
        "4.7.0",
        "4.6.1",
        "4.6.0",
        "4.5.2",
        "4.5.1",
        "4.5.0",
        "4.4.5",
        "4.4.4",
        "4.4.3",
        "4.4.2",
        "4.4.1",
        "4.4.0",
        "4.3.0",
        "4.2.3",
        "4.2.2",
        "4.2.1",
        "4.2.0",
        "4.1.0",
        "4.0.3",
        "4.0.2",
        "4.0.1",
        "4.0.0",
        "3.2.1",
        "3.2.0",
        "3.1.2",
        "3.1.1",
        "3.1.0",
        "3.0.3",
        "3.0.2",
        "3.0.1",
        "2.0.1",
        "2.0.0"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-112880"
  ],
  "credits": [
    {
      "name": "Daniel Coles",
      "type": "FINDER"
    },
    {
      "name": "Daniel Coles",
      "type": "REPORTER"
    },
    {
      "name": "Benoit Chesneau",
      "type": "REMEDIATION_DEVELOPER"
    },
    {
      "name": "Jonatan Männchen / EEF",
      "type": "COORDINATOR"
    }
  ],
  "database_specific": {
    "capec_ids": [
      "CAPEC-105"
    ],
    "cpe_ids": [
      "cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*"
    ],
    "cwe_ids": [
      "CWE-113"
    ]
  },
  "details": "## Summary\n\nImproper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting') vulnerability in `hackney_http_connect` in benoitc hackney allows HTTP Request Splitting via the value a `proxy_auth_fun` callback returns. After a 407 response from an HTTP CONNECT proxy, `hackney_http_connect:handle_proxy_auth/11` calls the caller's `proxy_auth_fun` with the status code and the response headers and writes the returned binary into the `Proxy-Authorization` line of the CONNECT retry without checking it. A CR, LF or NUL byte in that value adds header lines to the request sent to the proxy.\n\nThe value is attacker-influenced when the callback derives it from untrusted data, for example from the proxy's challenge headers. Other caller-supplied values on the CONNECT path, such as the target host and the request headers, were already checked for control bytes.\n\nThis issue affects hackney: from 2.0.0 before 4.9.0.\n\n## Details\n\n**1. Challenge.** `hackney_http_connect:do_handshake_with_auth/9` in `src/hackney_http_connect.erl` sends the CONNECT request to the proxy. When the proxy answers 407 and the `proxy_auth_fun` option is set, it hands the status code and the parsed response headers to `hackney_http_connect:handle_proxy_auth/11`.\n\n**2. Callback result.** `handle_proxy_auth/11` calls the caller's `proxy_auth_fun` with those two values. On `{ok, AuthHeader}` it removes any existing `Proxy-Authorization` header and appends the binary `<<\"Proxy-Authorization: \", AuthHeader/binary>>` to the header list, then retries the handshake with it.\n\n**3. Splitting.** The header list is joined with CRLF into the CONNECT request. A CR, LF or NUL byte inside `AuthHeader` therefore ends the `Proxy-Authorization` line early and the rest is sent as further header lines. The target host and the request headers go through control-byte checks on this path; the callback result did not. The fix applies the same `has_ctl_bytes/1` check to it and returns `{error, {proxy_auth_error, invalid_header}}`.\n\n## Impact\n\nA party who controls what the application's `proxy_auth_fun` returns, for instance through the challenge headers of a proxy it can influence, can add header lines to the CONNECT request the client sends to its proxy.\n\n## Workarounds\n\nCheck the value your `proxy_auth_fun` is about to return for CR, LF and NUL bytes and return `{error, Reason}` instead when one is present. The callback runs in the application, so the check can be made there.\n\n## Configurations\n\nThe client connects through an HTTP CONNECT proxy with the `proxy_auth_fun` option set, and the callback builds its result from data an untrusted party can influence, such as the proxy's 407 challenge headers. Deployments without `proxy_auth_fun`, or whose callback returns a fixed credential, are not affected.",
  "id": "EEF-CVE-2026-112880",
  "modified": "2026-10-26T14:00:04.842750062Z",
  "published": "2026-10-26T13:48:46.589Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/benoitc/hackney/releases/tag/4.9.0"
    },
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-112880.html"
    },
    {
      "type": "WEB",
      "url": "https://github.com/benoitc/hackney/pull/989"
    },
    {
      "type": "WEB",
      "url": "https://github.com/benoitc/hackney/commit/5df5a74a2817d5b12880d217db33253ff1fae1b5"
    },
    {
      "type": "FIX",
      "url": "https://github.com/benoitc/hackney/commit/5ee7d7d19eba27e774667d472feb1e93a08af7f9"
    },
    {
      "type": "PACKAGE",
      "url": "https://hex.pm/packages/hackney"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "CRLF injection in Proxy-Authorization header built from proxy_auth_fun in hackney"
}