{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "27.0"
              },
              {
                "fixed": "27.3.4.12"
              },
              {
                "introduced": "28.0"
              },
              {
                "fixed": "28.5.0.1"
              },
              {
                "introduced": "29.0"
              },
              {
                "fixed": "29.0.1"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "601a012837ea0a5c8095bf24223132824177124d"
            },
            {
              "fixed": "a2394acad3e3b8fa74d40905cb79bac2ab68258a"
            },
            {
              "introduced": "9e6f6742c4d9e9915ee8af0dcb7d97cf1f836116"
            },
            {
              "fixed": "5770157eabdd4e8b0b83d64fd8b207c0150c2b64"
            },
            {
              "introduced": "550d7b7898706c7822362c42e7b93120c1d1f29a"
            },
            {
              "fixed": "f26c7e590c5d1b3afa0dee38093442df117822e3"
            },
            {
              "fixed": "7995f1fdaee3da569bb810358ce0f546471d169b"
            },
            {
              "fixed": "b3870e02405c709a872b01ba6086065620cdfe76"
            }
          ],
          "repo": "https://github.com/erlang/otp",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-cjxj-wj6x-3fff"
  ],
  "database_specific": {
    "cna_assigner": "EEF",
    "cwe_ids": [
      "CWE-295",
      "CWE-672"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42791.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "1.16"
          },
          {
            "fixed": "*"
          },
          {
            "introduced": "27.0"
          },
          {
            "fixed": "*"
          },
          {
            "introduced": "2b1a742c651b90f8a7a1fb2ddde73f29915ea376"
          },
          {
            "fixed": "*"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Improper Certificate Validation vulnerability in Erlang OTP public_key (pubkey_ocsp module) allows forged OCSP responses signed with an expired responder certificate to be accepted as valid.\n\nOCSP response verification in pubkey_ocsp:verify_response/5 and pubkey_ocsp:is_authorized_responder/3 in lib/public_key/src/pubkey_ocsp.erl does not check the validity period (notBefore/notAfter) of the OCSP responder certificate. An attacker who has obtained the private key of an expired CA-designated OCSP responder certificate can forge OCSP responses that Erlang/OTP accepts as valid.\n\nThis affects TLS clients using OCSP stapling via the ssl application: a malicious or compromised server can present a revoked TLS certificate together with a forged OCSP response signed by an expired responder key, and the client will accept the revoked certificate as valid. It also affects applications calling public_key:pkix_ocsp_validate/5 directly, where the impact depends on the use case — server-side client certificate validation using this API may allow authentication bypass with a revoked client certificate.\n\nThis issue affects OTP from OTP 27.0 before OTP 27.3.4.12, 28.5.0.1, and 29.0.1 corresponding to public_key from 1.16 before 1.17.1.3, 1.20.3.1, and 1.21.1.",
  "id": "CVE-2026-42791",
  "modified": "2026-07-15T01:49:04.278021103Z",
  "published": "2026-05-27T12:23:13.584Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-42791.html"
    },
    {
      "type": "WEB",
      "url": "https://github.com"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-42791"
    },
    {
      "type": "WEB",
      "url": "https://www.erlang.org/doc/system/versions.html#order-of-versions"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42791.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/erlang/otp/security/advisories/GHSA-cjxj-wj6x-3fff"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42791"
    },
    {
      "type": "FIX",
      "url": "https://github.com/erlang/otp/commit/7995f1fdaee3da569bb810358ce0f546471d169b"
    },
    {
      "type": "FIX",
      "url": "https://github.com/erlang/otp/commit/b3870e02405c709a872b01ba6086065620cdfe76"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/erlang/otp"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "OCSP responder certificate validity period not checked in public_key"
}