{
  "containers": {
    "cna": {
      "affected": [
        {
          "collectionURL": "https://repo.hex.pm",
          "cpes": [
            "cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "hackney_url"
          ],
          "packageName": "hackney",
          "packageURL": "pkg:hex/hackney",
          "product": "hackney",
          "programFiles": [
            "src/hackney_url.erl"
          ],
          "programRoutines": [
            {
              "name": "hackney_url:normalize/2"
            }
          ],
          "repo": "https://github.com/benoitc/hackney",
          "vendor": "benoitc",
          "versions": [
            {
              "lessThan": "4.9.0",
              "status": "affected",
              "version": "4.0.1",
              "versionType": "semver"
            }
          ]
        },
        {
          "collectionURL": "https://github.com",
          "cpes": [
            "cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "hackney_url"
          ],
          "packageName": "benoitc/hackney",
          "packageURL": "pkg:github/benoitc/hackney",
          "product": "hackney",
          "programFiles": [
            "src/hackney_url.erl"
          ],
          "programRoutines": [
            {
              "name": "hackney_url:normalize/2"
            }
          ],
          "repo": "https://github.com/benoitc/hackney",
          "vendor": "benoitc",
          "versions": [
            {
              "lessThan": "f19561a0b422376348c91537e51377ab7325f4ee",
              "status": "affected",
              "version": "452620a92ec1da2e6b4862a049a2a4f04b42068f",
              "versionType": "git"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eThe application passes URLs that an untrusted party can influence to hackney and relies on its own host allowlist, built on \u003ccode\u003euri_string:parse/1\u003c/code\u003e or \u003ccode\u003einet:parse_address/1\u003c/code\u003e, to keep requests away from internal addresses.\u003c/p\u003e"
            },
            {
              "base64": false,
              "type": "text/markdown",
              "value": "The application passes URLs that an untrusted party can influence to hackney and relies on its own host allowlist, built on `uri_string:parse/1` or `inet:parse_address/1`, to keep requests away from internal addresses."
            }
          ],
          "value": "The application passes URLs that an untrusted party can influence to hackney and relies on its own host allowlist, built on uri_string:parse/1 or inet:parse_address/1, to keep requests away from internal addresses."
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.9.0",
                  "versionStartIncluding": "4.0.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ],
          "operator": "AND"
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Eurico Nicacio"
        },
        {
          "lang": "en",
          "type": "reporter",
          "value": "Eurico Nicacio"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Benoit Chesneau"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "Jonatan M\u00e4nnchen / EEF"
        }
      ],
      "dateAssigned": "2026-10-26T10:12:09.000Z",
      "datePublic": "2026-10-25T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eInterpretation Conflict vulnerability in \u003ccode\u003ehackney_url\u003c/code\u003e in benoitc hackney allows Server Side Request Forgery via a percent-encoded bracketed IPv6 literal or an IP literal with a trailing dot. A host such as \u003ccode\u003e%5B%3A%3Affff%3A127%2E0%2E0%2E1%5D\u003c/code\u003e (decoding to \u003ccode\u003e[::ffff:127.0.0.1]\u003c/code\u003e) or \u003ccode\u003e127.0.0.1.\u003c/code\u003e is not an IP address to a caller\u0027s allowlist built on \u003ccode\u003euri_string:parse/1\u003c/code\u003e and \u003ccode\u003einet:parse_address/1\u003c/code\u003e, while hackney connects to the address it denotes. The same applies to a \u003ccode\u003eLocation\u003c/code\u003e target when redirects are followed.\u003c/p\u003e\n\u003cp\u003eThe IP-literal gate that \u003ccode\u003ehackney_url:normalize/2\u003c/code\u003e applies to a percent-decoded host, added to close the percent-encoded IP bypass of CVE-2026-47076, passes the decoded value to \u003ccode\u003einet_parse:address/1\u003c/code\u003e as is. The connect path in \u003ccode\u003ehackney_happy:parse_address/1\u003c/code\u003e drops a surrounding bracket pair, and the resolver ignores a trailing dot, so both forms pass the gate and still reach the literal address. Domain names with a trailing dot and unencoded IPv6 literals are not affected.\u003c/p\u003e\n\u003cp\u003eThis issue affects hackney: from 4.0.1 before 4.9.0.\u003c/p\u003e"
            },
            {
              "base64": false,
              "type": "text/markdown",
              "value": "Interpretation Conflict vulnerability in `hackney_url` in benoitc hackney allows Server Side Request Forgery via a percent-encoded bracketed IPv6 literal or an IP literal with a trailing dot. A host such as `%5B%3A%3Affff%3A127%2E0%2E0%2E1%5D` (decoding to `[::ffff:127.0.0.1]`) or `127.0.0.1.` is not an IP address to a caller\u0027s allowlist built on `uri_string:parse/1` and `inet:parse_address/1`, while hackney connects to the address it denotes. The same applies to a `Location` target when redirects are followed.\n\nThe IP-literal gate that `hackney_url:normalize/2` applies to a percent-decoded host, added to close the percent-encoded IP bypass of CVE-2026-47076, passes the decoded value to `inet_parse:address/1` as is. The connect path in `hackney_happy:parse_address/1` drops a surrounding bracket pair, and the resolver ignores a trailing dot, so both forms pass the gate and still reach the literal address. Domain names with a trailing dot and unencoded IPv6 literals are not affected.\n\nThis issue affects hackney: from 4.0.1 before 4.9.0."
            }
          ],
          "value": "Interpretation Conflict vulnerability in hackney_url in benoitc hackney allows Server Side Request Forgery via a percent-encoded bracketed IPv6 literal or an IP literal with a trailing dot. A host such as %5B%3A%3Affff%3A127%2E0%2E0%2E1%5D (decoding to [::ffff:127.0.0.1]) or 127.0.0.1. is not an IP address to a caller\u0027s allowlist built on uri_string:parse/1 and inet:parse_address/1, while hackney connects to the address it denotes. The same applies to a Location target when redirects are followed.\n\nThe IP-literal gate that hackney_url:normalize/2 applies to a percent-decoded host, added to close the percent-encoded IP bypass of CVE-2026-47076, passes the decoded value to inet_parse:address/1 as is. The connect path in hackney_happy:parse_address/1 drops a surrounding bracket pair, and the resolver ignores a trailing dot, so both forms pass the gate and still reach the literal address. Domain names with a trailing dot and unencoded IPv6 literals are not affected.\n\nThis issue affects hackney: from 4.0.1 before 4.9.0."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-664",
          "descriptions": [
            {
              "lang": "en",
              "supportingMedia": [
                {
                  "base64": false,
                  "type": "text/html",
                  "value": "\u003cp\u003eAn application that checks user-supplied URLs against an IP allowlist before handing them to hackney can be made to request loopback, link-local metadata and private-network addresses that the allowlist rejects when they are written plainly.\u003c/p\u003e"
                },
                {
                  "base64": false,
                  "type": "text/markdown",
                  "value": "An application that checks user-supplied URLs against an IP allowlist before handing them to hackney can be made to request loopback, link-local metadata and private-network addresses that the allowlist rejects when they are written plainly."
                }
              ],
              "value": "An application that checks user-supplied URLs against an IP allowlist before handing them to hackney can be made to request loopback, link-local metadata and private-network addresses that the allowlist rejects when they are written plainly."
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "LOCAL",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "HIGH",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-436",
              "description": "CWE-436 Interpretation Conflict",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-918",
              "description": "CWE-918 Server-Side Request Forgery (SSRF)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-26T13:49:02.744Z",
        "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "shortName": "EEF"
      },
      "references": [
        {
          "name": "hackney 4.9.0 release notes",
          "tags": [
            "vendor-advisory",
            "related"
          ],
          "url": "https://github.com/benoitc/hackney/releases/tag/4.9.0"
        },
        {
          "name": "EEF CNA record for CVE-2026-115700",
          "tags": [
            "related"
          ],
          "url": "https://cna.erlef.org/cves/CVE-2026-115700.html"
        },
        {
          "name": "OSV record EEF-CVE-2026-115700",
          "tags": [
            "related"
          ],
          "url": "https://osv.dev/vulnerability/EEF-CVE-2026-115700"
        },
        {
          "name": "Refuse bracketed and trailing-dot IP literals in normalize/2 (benoitc/hackney#987)",
          "tags": [
            "related"
          ],
          "url": "https://github.com/benoitc/hackney/pull/987"
        },
        {
          "name": "Introducing commit 452620a in benoitc/hackney",
          "tags": [
            "related"
          ],
          "url": "https://github.com/benoitc/hackney/commit/452620a92ec1da2e6b4862a049a2a4f04b42068f"
        },
        {
          "name": "Fix commit f19561a in benoitc/hackney",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/benoitc/hackney/commit/f19561a0b422376348c91537e51377ab7325f4ee"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "SSRF allowlist bypass via percent-encoded bracketed IPv6 or trailing-dot IP literal in hackney",
      "workarounds": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eRun the allowlist on the host that \u003ccode\u003ehackney_url:normalize/1\u003c/code\u003e returns for the parsed URL, and strip a surrounding bracket pair and a trailing dot from it before the IP check, so the check sees the same address the connect path uses.\u003c/p\u003e"
            },
            {
              "base64": false,
              "type": "text/markdown",
              "value": "Run the allowlist on the host that `hackney_url:normalize/1` returns for the parsed URL, and strip a surrounding bracket pair and a trailing dot from it before the IP check, so the check sees the same address the connect path uses."
            }
          ],
          "value": "Run the allowlist on the host that hackney_url:normalize/1 returns for the parsed URL, and strip a surrounding bracket pair and a trailing dot from it before the IP check, so the check sees the same address the connect path uses."
        }
      ],
      "x_technicalAnalysis": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003e\u003cstrong\u003e1. The gate.\u003c/strong\u003e \u003ccode\u003ehackney_url:normalize/2\u003c/code\u003e in \u003ccode\u003esrc/hackney_url.erl\u003c/code\u003e percent-decodes a host that is not already an IP literal and raises \u003ccode\u003einvalid_url_host\u003c/code\u003e when \u003ccode\u003einet_parse:address/1\u003c/code\u003e accepts the decoded value. This closed the plain percent-encoded IP case.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2. What the connect path accepts.\u003c/strong\u003e \u003ccode\u003ehackney_happy:parse_address/1\u003c/code\u003e removes a surrounding \u003ccode\u003e[...]\u003c/code\u003e pair before calling \u003ccode\u003einet:parse_address/1\u003c/code\u003e, and the resolver treats a trailing dot as the root label. Neither form is accepted by \u003ccode\u003einet_parse:address/1\u003c/code\u003e, so \u003ccode\u003e[::ffff:127.0.0.1]\u003c/code\u003e and \u003ccode\u003e127.0.0.1.\u003c/code\u003e pass the gate.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3. Result.\u003c/strong\u003e A percent-encoded bracketed IPv6 literal such as \u003ccode\u003e%5B%3A%3Affff%3A127%2E0%2E0%2E1%5D\u003c/code\u003e, or an IPv4 literal with a trailing dot, is not an IP address to a caller\u0027s check based on \u003ccode\u003euri_string:parse/1\u003c/code\u003e and \u003ccode\u003einet:parse_address/1\u003c/code\u003e, but hackney connects to the address it denotes. The same applies to a \u003ccode\u003eLocation\u003c/code\u003e target when redirects are followed. The fix strips one bracket pair and one trailing dot in \u003ccode\u003eip_candidate/1\u003c/code\u003e before the gate.\u003c/p\u003e"
            },
            {
              "base64": false,
              "type": "text/markdown",
              "value": "**1. The gate.** `hackney_url:normalize/2` in `src/hackney_url.erl` percent-decodes a host that is not already an IP literal and raises `invalid_url_host` when `inet_parse:address/1` accepts the decoded value. This closed the plain percent-encoded IP case.\n\n**2. What the connect path accepts.** `hackney_happy:parse_address/1` removes a surrounding `[...]` pair before calling `inet:parse_address/1`, and the resolver treats a trailing dot as the root label. Neither form is accepted by `inet_parse:address/1`, so `[::ffff:127.0.0.1]` and `127.0.0.1.` pass the gate.\n\n**3. Result.** A percent-encoded bracketed IPv6 literal such as `%5B%3A%3Affff%3A127%2E0%2E0%2E1%5D`, or an IPv4 literal with a trailing dot, is not an IP address to a caller\u0027s check based on `uri_string:parse/1` and `inet:parse_address/1`, but hackney connects to the address it denotes. The same applies to a `Location` target when redirects are followed. The fix strips one bracket pair and one trailing dot in `ip_candidate/1` before the gate."
            }
          ],
          "value": "1. The gate. hackney_url:normalize/2 in src/hackney_url.erl percent-decodes a host that is not already an IP literal and raises invalid_url_host when inet_parse:address/1 accepts the decoded value. This closed the plain percent-encoded IP case.\n\n2. What the connect path accepts. hackney_happy:parse_address/1 removes a surrounding [...] pair before calling inet:parse_address/1, and the resolver treats a trailing dot as the root label. Neither form is accepted by inet_parse:address/1, so [::ffff:127.0.0.1] and 127.0.0.1. pass the gate.\n\n3. Result. A percent-encoded bracketed IPv6 literal such as %5B%3A%3Affff%3A127%2E0%2E0%2E1%5D, or an IPv4 literal with a trailing dot, is not an IP address to a caller\u0027s check based on uri_string:parse/1 and inet:parse_address/1, but hackney connects to the address it denotes. The same applies to a Location target when redirects are followed. The fix strips one bracket pair and one trailing dot in ip_candidate/1 before the gate."
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
    "assignerShortName": "EEF",
    "cveId": "CVE-2026-115700",
    "datePublished": "2026-10-26T13:49:02.744Z",
    "dateReserved": "2026-10-25T17:30:02.231Z",
    "dateUpdated": "2026-10-26T13:49:02.744Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}