erlang-hex — security advisory

{
  "id": "b863e1475665c6ae5c2093e9002e09001883e9d189d77284a4c74d40f7b5e371",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-103502",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2026-103502",
    "summary": "Improper Certificate Validation vulnerability in hexpm hex_core allows an attacker who can intercept HTTPS connections to impersonate hex.pm, repo.hex.pm or any other repository or API server to programs that use hex_core's default HTTP adapter on Erlang/OTP 24, or on OTP 25 when the operating system's CA certificates can't be loaded. hex_core:default_config/0 selects the built-in hex_http_httpc adapter. For an HTTPS request whose adapter config has no ssl option, hex_http_httpc:http_options/2 builds options that verify the server certificate against public_key:cacerts_get/0. When that call raises, the adapter prints a warning and sends the request without ssl options, so httpc uses the defaults of the ssl application, which before OTP 26 don't verify the server certificate. public_key:cacerts_get/0 doesn't exist on OTP 24, so every HTTPS request falls back there, and on OTP 25 it raises when no CA store is found. hex_core versions before 0.11.0 never set ssl options, so they don't verify the server certificate on OTP 25 and earlier whether or not a CA store is found. The fallback was intended and documented, but the documentation didn't make clear that it meant no certificate verification. Since hex_core 0.8.2 the README has warned that the built-in httpc adapter \"has insecure default settings\" and recommended other HTTP clients, and the adapter prints \"using default ssl options which are insecure\" on every request that falls back. hex_core 0.11.0 added certificate verificat",
    "evidence": "osv:DEBIAN-CVE-2026-103502",
    "products": [
      {
        "name": {
          "value": "erlang-hex",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.0.6-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.4.2-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.4.2-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.5.1-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.5.1-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.5.3-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.5.3-2",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "erlang-hex",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.5.3-2",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "2.0.6-2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.4.2-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.4.2-2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.5.1-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.5.1-2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.5.3-1",
            "evidence": "/affected/1/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "DEBIAN-CVE-2026-103502",
      "aliases": [
        "DEBIAN-CVE-2026-103502"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "erlang-hex",
            "purl": "pkg:deb/debian/erlang-hex?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "versions": [
            "2.0.6-2",
            "2.4.2-1",
            "2.4.2-2",
            "2.5.1-1",
            "2.5.1-2",
            "2.5.3-1",
            "2.5.3-2"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-103502.json"
          },
          "ecosystem_specific": {
            "urgency": "unimportant"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.5.3-2"
                }
              ]
            }
          ],
          "package": {
            "name": "erlang-hex",
            "purl": "pkg:deb/debian/erlang-hex?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "versions": [
            "2.0.6-2",
            "2.4.2-1",
            "2.4.2-2",
            "2.5.1-1",
            "2.5.1-2",
            "2.5.3-1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-103502.json"
          },
          "ecosystem_specific": {
            "urgency": "unimportant"
          }
        }
      ],
      "modified": "2026-10-23T17:47:28.961671429Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-103502"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2026-103502"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-103502",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 417168,
  "published_at": "2026-10-12T14:17:08.61+00:00"
}