FKIE_CVE-2026-103502

Vulnerability from fkie_nvd - Published: 2026-10-12 14:17 - Updated: 2026-10-13 14:31
Severity
5.9 (Medium) - 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
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 verification with the changelog entry "Use secure SSL defaults for OTP 25+". Neither the README nor the warning says that the server certificate isn't verified, the README doesn't say which OTP versions the warning applies to, and on OTP 25 without CA certificates the warning tells users to upgrade to OTP 25 or later, which they already run. This advisory is published so that users who took those notices as general advice know their HTTPS requests weren't authenticated. This issue affects hex_core: from 0.1.0 before 0.20.0.
References
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://cna.erlef.org/cves/CVE-2026-103502.html
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/hexpm/hex_core/commit/b7b3a42defb4ed8e20a5c68a4412ce68a95b7938
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/hexpm/hex_core/commit/fbb6d9de472e5edb8d6fb6b32a91cb266137892e
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/hexpm/hex_core/security/advisories/GHSA-p26c-h8c2-rwqj
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://osv.dev/vulnerability/EEF-CVE-2026-103502
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://repo.hex.pm",
          "cpes": [
            "cpe:2.3:a:hexpm:hex_core:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "hex_http_httpc"
          ],
          "packageName": "hex_core",
          "packageURL": "pkg:hex/hex_core",
          "product": "hex_core",
          "programFiles": [
            "src/hex_http_httpc.erl"
          ],
          "programRoutines": [
            {
              "name": "hex_http_httpc:request/5"
            },
            {
              "name": "hex_http_httpc:request_to_file/6"
            }
          ],
          "repo": "https://github.com/hexpm/hex_core",
          "vendor": "hexpm",
          "versions": [
            {
              "lessThan": "0.20.0",
              "status": "affected",
              "version": "0.1.0",
              "versionType": "semver"
            }
          ]
        },
        {
          "collectionURL": "https://github.com",
          "cpes": [
            "cpe:2.3:a:hexpm:hex_core:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "hex_http_httpc"
          ],
          "packageName": "hexpm/hex_core",
          "packageURL": "pkg:github/hexpm/hex_core",
          "product": "hex_core",
          "programFiles": [
            "src/hex_http_httpc.erl"
          ],
          "programRoutines": [
            {
              "name": "hex_http_httpc:request/5"
            },
            {
              "name": "hex_http_httpc:request_to_file/6"
            }
          ],
          "repo": "https://github.com/hexpm/hex_core",
          "vendor": "hexpm",
          "versions": [
            {
              "lessThan": "b7b3a42defb4ed8e20a5c68a4412ce68a95b7938",
              "status": "affected",
              "version": "fbb6d9de472e5edb8d6fb6b32a91cb266137892e",
              "versionType": "git"
            }
          ]
        }
      ],
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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\u0027s default HTTP adapter on Erlang/OTP 24, or on OTP 25 when the operating system\u0027s CA certificates can\u0027t be loaded.\n\nhex_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\u0027t verify the server certificate. public_key:cacerts_get/0 doesn\u0027t 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\u0027t verify the server certificate on OTP 25 and earlier whether or not a CA store is found.\n\nThe fallback was intended and documented, but the documentation didn\u0027t 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 verification with the changelog entry \"Use secure SSL defaults for OTP 25+\". Neither the README nor the warning says that the server certificate isn\u0027t verified, the README doesn\u0027t say which OTP versions the warning applies to, and on OTP 25 without CA certificates the warning tells users to upgrade to OTP 25 or later, which they already run. This advisory is published so that users who took those notices as general advice know their HTTPS requests weren\u0027t authenticated.\n\nThis issue affects hex_core: from 0.1.0 before 0.20.0."
    }
  ],
  "id": "CVE-2026-103502",
  "lastModified": "2026-10-13T14:31:20.750",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 5.9,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "ACTIVE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "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",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "LOW",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-10-12T14:17:08.610",
  "references": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://cna.erlef.org/cves/CVE-2026-103502.html"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/hexpm/hex_core/commit/b7b3a42defb4ed8e20a5c68a4412ce68a95b7938"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/hexpm/hex_core/commit/fbb6d9de472e5edb8d6fb6b32a91cb266137892e"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/hexpm/hex_core/security/advisories/GHSA-p26c-h8c2-rwqj"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-103502"
    }
  ],
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-295"
        },
        {
          "lang": "en",
          "value": "CWE-636"
        }
      ],
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "type": "Secondary"
    }
  ]
}



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