CRLF injection in Proxy-Authorization header built from proxy_auth_fun in hackney

{
  "id": "5045973ff56c3bad2c061c09bd3fa3bc0d894108e1eee7a212aa56dcb3d04834",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-112880",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CRLF injection in Proxy-Authorization header built from proxy_auth_fun in hackney",
    "summary": "Improper 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. The 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. This issue affects hackney: from 2.0.0 before 4.9.0.",
    "evidence": "cve:CVE-2026-112880",
    "products": [
      {
        "name": {
          "value": "hackney",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      },
      {
        "name": {
          "value": "hackney",
          "evidence": "/containers/cna/affected/1/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "low",
    "structured": {
      "id": "CVE-2026-112880",
      "aliases": [
        "CVE-2026-112880"
      ],
      "metrics": [
        {
          "format": "CVSS",
          "cvssV4_0": {
            "Safety": "NOT_DEFINED",
            "version": "4.0",
            "Recovery": "NOT_DEFINED",
            "baseScore": 2.1,
            "Automatable": "NOT_DEFINED",
            "attackVector": "LOCAL",
            "baseSeverity": "LOW",
            "valueDensity": "NOT_DEFINED",
            "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",
            "providerUrgency": "NOT_DEFINED",
            "userInteraction": "NONE",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "privilegesRequired": "NONE",
            "subIntegrityImpact": "LOW",
            "vulnIntegrityImpact": "LOW",
            "subAvailabilityImpact": "NONE",
            "vulnAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "affected": [
        {
          "cpes": [
            "cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*"
          ],
          "repo": "https://github.com/benoitc/hackney",
          "vendor": "benoitc",
          "modules": [
            "hackney_http_connect"
          ],
          "product": "hackney",
          "versions": [
            {
              "status": "affected",
              "version": "2.0.0",
              "lessThan": "4.9.0",
              "versionType": "semver"
            }
          ],
          "packageURL": "pkg:hex/hackney",
          "packageName": "hackney",
          "programFiles": [
            "src/hackney_http_connect.erl"
          ],
          "collectionURL": "https://repo.hex.pm",
          "defaultStatus": "unaffected",
          "programRoutines": [
            {
              "name": "hackney_http_connect:connect/4"
            },
            {
              "name": "hackney_http_connect:do_handshake_with_auth/9"
            },
            {
              "name": "hackney_http_connect:handle_proxy_auth/11"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*"
          ],
          "repo": "https://github.com/benoitc/hackney",
          "vendor": "benoitc",
          "modules": [
            "hackney_http_connect"
          ],
          "product": "hackney",
          "versions": [
            {
              "status": "affected",
              "version": "5df5a74a2817d5b12880d217db33253ff1fae1b5",
              "lessThan": "5ee7d7d19eba27e774667d472feb1e93a08af7f9",
              "versionType": "git"
            }
          ],
          "packageURL": "pkg:github/benoitc/hackney",
          "packageName": "benoitc/hackney",
          "programFiles": [
            "src/hackney_http_connect.erl"
          ],
          "collectionURL": "https://github.com",
          "defaultStatus": "unaffected",
          "programRoutines": [
            {
              "name": "hackney_http_connect:connect/4"
            },
            {
              "name": "hackney_http_connect:do_handshake_with_auth/9"
            },
            {
              "name": "hackney_http_connect:handle_proxy_auth/11"
            }
          ]
        }
      ],
      "modified": "2026-10-26T15:35:50.632Z",
      "provider": "cve",
      "references": [
        "https://github.com/benoitc/hackney/releases/tag/4.9.0",
        "https://cna.erlef.org/cves/CVE-2026-112880.html",
        "https://osv.dev/vulnerability/EEF-CVE-2026-112880",
        "https://github.com/benoitc/hackney/pull/989",
        "https://github.com/benoitc/hackney/commit/5df5a74a2817d5b12880d217db33253ff1fae1b5",
        "https://github.com/benoitc/hackney/commit/5ee7d7d19eba27e774667d472feb1e93a08af7f9"
      ],
      "provider_metadata": {
        "adp": [
          {
            "title": "CISA ADP Vulnrichment",
            "metrics": [
              {
                "other": {
                  "type": "ssvc",
                  "content": {
                    "id": "CVE-2026-112880",
                    "role": "CISA Coordinator",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "version": "2.0.3",
                    "timestamp": "2026-10-26T15:00:47.038622Z"
                  }
                }
              }
            ],
            "providerMetadata": {
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP",
              "dateUpdated": "2026-10-26T15:35:50.632Z"
            }
          }
        ],
        "cna": {
          "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
          "shortName": "EEF",
          "dateUpdated": "2026-10-26T13:48:46.589Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-112880",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 316043,
  "published_at": "2026-10-26T13:48:46.589+00:00"
}