{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-42791",
        "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "state": "PUBLISHED",
        "assignerShortName": "EEF",
        "dateReserved": "2026-04-29T18:06:33.251Z",
        "datePublished": "2026-05-27T12:23:13.584Z",
        "dateUpdated": "2026-07-24T14:14:24.911Z"
    },
    "containers": {
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            "affected": [
                {
                    "cpes": [
                        "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"
                    ],
                    "defaultStatus": "unknown",
                    "modules": [
                        "pubkey_ocsp"
                    ],
                    "packageName": "public_key",
                    "packageURL": "pkg:otp/public_key?repository_url=https:%2F%2Fgithub.com%2Ferlang%2Fotp&vcs_url=git%20https:%2F%2Fgithub.com%2Ferlang%2Fotp.git",
                    "product": "OTP",
                    "programFiles": [
                        "src/pubkey_ocsp.erl"
                    ],
                    "programRoutines": [
                        {
                            "name": "pubkey_ocsp:verify_response/5"
                        },
                        {
                            "name": "pubkey_ocsp:is_authorized_responder/3"
                        }
                    ],
                    "repo": "https://github.com/erlang/otp",
                    "vendor": "Erlang",
                    "versions": [
                        {
                            "changes": [
                                {
                                    "at": "1.17.1.3",
                                    "status": "unaffected"
                                },
                                {
                                    "at": "1.20.3.1",
                                    "status": "unaffected"
                                },
                                {
                                    "at": "1.21.1",
                                    "status": "unaffected"
                                }
                            ],
                            "lessThan": "*",
                            "status": "affected",
                            "version": "1.16",
                            "versionType": "otp"
                        }
                    ]
                },
                {
                    "collectionURL": "https://github.com",
                    "cpes": [
                        "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"
                    ],
                    "defaultStatus": "unknown",
                    "modules": [
                        "pubkey_ocsp"
                    ],
                    "packageName": "erlang/otp",
                    "packageURL": "pkg:github/erlang/otp",
                    "product": "OTP",
                    "programFiles": [
                        "lib/public_key/src/pubkey_ocsp.erl"
                    ],
                    "programRoutines": [
                        {
                            "name": "pubkey_ocsp:verify_response/5"
                        },
                        {
                            "name": "pubkey_ocsp:is_authorized_responder/3"
                        }
                    ],
                    "repo": "https://github.com/erlang/otp",
                    "vendor": "Erlang",
                    "versions": [
                        {
                            "changes": [
                                {
                                    "at": "27.3.4.12",
                                    "status": "unaffected"
                                },
                                {
                                    "at": "28.5.0.1",
                                    "status": "unaffected"
                                },
                                {
                                    "at": "29.0.1",
                                    "status": "unaffected"
                                }
                            ],
                            "lessThan": "*",
                            "status": "affected",
                            "version": "27.0",
                            "versionType": "otp"
                        },
                        {
                            "changes": [
                                {
                                    "at": "7995f1fdaee3da569bb810358ce0f546471d169b",
                                    "status": "unaffected"
                                },
                                {
                                    "at": "b3870e02405c709a872b01ba6086065620cdfe76",
                                    "status": "unaffected"
                                }
                            ],
                            "lessThan": "*",
                            "status": "affected",
                            "version": "2b1a742c651b90f8a7a1fb2ddde73f29915ea376",
                            "versionType": "git"
                        }
                    ]
                }
            ],
            "configurations": [
                {
                    "lang": "en",
                    "supportingMedia": [
                        {
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                            "type": "text/html",
                            "value": "For the <tt>ssl</tt> application, OCSP stapling must be enabled by setting the <tt>stapling</tt> option to <tt>staple</tt> in the TLS client options. OCSP stapling is not enabled by default.<p>Applications calling <tt>public_key:pkix_ocsp_validate/5</tt> directly are unconditionally affected when that function is used.</p>"
                        }
                    ],
                    "value": "For the ssl application, OCSP stapling must be enabled by setting the stapling option to staple in the TLS client options. OCSP stapling is not enabled by default.\n\nApplications calling public_key:pkix_ocsp_validate/5 directly are unconditionally affected when that function is used."
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "cpeMatch": [
                                {
                                    "criteria": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
                                    "versionEndExcluding": "27.3.4.12",
                                    "versionStartIncluding": "27.0",
                                    "vulnerable": true
                                },
                                {
                                    "criteria": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
                                    "versionEndExcluding": "28.5.0.1",
                                    "versionStartIncluding": "28.0",
                                    "vulnerable": true
                                },
                                {
                                    "criteria": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
                                    "versionEndExcluding": "29.0.1",
                                    "versionStartIncluding": "29.0",
                                    "vulnerable": true
                                }
                            ],
                            "negate": false,
                            "operator": "OR"
                        }
                    ],
                    "operator": "AND"
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "type": "remediation developer",
                    "value": "Jakub Witczak"
                },
                {
                    "lang": "en",
                    "type": "remediation reviewer",
                    "value": "Ingela Anderton Andin"
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "supportingMedia": [
                        {
                            "base64": false,
                            "type": "text/html",
                            "value": "Improper Certificate Validation vulnerability in Erlang OTP <tt>public_key</tt> (<tt>pubkey_ocsp</tt> module) allows forged OCSP responses signed with an expired responder certificate to be accepted as valid.<p>OCSP response verification in <tt>pubkey_ocsp:verify_response/5</tt> and <tt>pubkey_ocsp:is_authorized_responder/3</tt> in <tt>lib/public_key/src/pubkey_ocsp.erl</tt> does not check the validity period (<tt>notBefore</tt>/<tt>notAfter</tt>) 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.</p><p>This affects TLS clients using OCSP stapling via the <tt>ssl</tt> 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 <tt>public_key:pkix_ocsp_validate/5</tt> 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.</p><p>This issue affects OTP from OTP 27.0 before OTP&nbsp;29.0.1, OTP&nbsp;28.5.0.1 and OTP&nbsp;27.3.4.12, corresponding to <tt>public_key</tt> from 1.16 before 1.21.1, 1.20.3.1 and 1.17.1.3.</p>"
                        }
                    ],
                    "value": "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 29.0.1, OTP 28.5.0.1 and OTP 27.3.4.12, corresponding to public_key from 1.16 before 1.21.1, 1.20.3.1 and 1.17.1.3."
                }
            ],
            "impacts": [
                {
                    "capecId": "CAPEC-475",
                    "descriptions": [
                        {
                            "lang": "en",
                            "value": "CAPEC-475 Signature Spoofing by Improper Validation"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackComplexity": "HIGH",
                        "attackRequirements": "PRESENT",
                        "attackVector": "NETWORK",
                        "baseScore": 6.3,
                        "baseSeverity": "MEDIUM",
                        "privilegesRequired": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "LOW",
                        "subIntegrityImpact": "LOW",
                        "userInteraction": "NONE",
                        "vectorString": "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",
                        "version": "4.0",
                        "vulnAvailabilityImpact": "NONE",
                        "vulnConfidentialityImpact": "NONE",
                        "vulnIntegrityImpact": "LOW"
                    },
                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
                        }
                    ]
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            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-295",
                            "description": "CWE-295 Improper Certificate Validation",
                            "lang": "en",
                            "type": "CWE"
                        },
                        {
                            "cweId": "CWE-672",
                            "description": "CWE-672 Operation on a Resource after Expiration or Release",
                            "lang": "en",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
                "shortName": "EEF",
                "dateUpdated": "2026-07-24T14:14:24.911Z"
            },
            "references": [
                {
                    "tags": [
                        "vendor-advisory",
                        "related"
                    ],
                    "url": "https://github.com/erlang/otp/security/advisories/GHSA-cjxj-wj6x-3fff"
                },
                {
                    "tags": [
                        "related"
                    ],
                    "url": "https://cna.erlef.org/cves/CVE-2026-42791.html"
                },
                {
                    "tags": [
                        "related"
                    ],
                    "url": "https://osv.dev/vulnerability/EEF-CVE-2026-42791"
                },
                {
                    "tags": [
                        "x_version-scheme"
                    ],
                    "url": "https://www.erlang.org/doc/system/versions.html#order-of-versions"
                },
                {
                    "tags": [
                        "patch"
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                    "url": "https://github.com/erlang/otp/commit/7995f1fdaee3da569bb810358ce0f546471d169b"
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                    "url": "https://github.com/erlang/otp/commit/b3870e02405c709a872b01ba6086065620cdfe76"
                }
            ],
            "source": {
                "discovery": "INTERNAL"
            },
            "title": "OCSP responder certificate validity period not checked in public_key",
            "workarounds": [
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                    "supportingMedia": [
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                            "value": "<ul><li>For TLS clients using the <tt>ssl</tt> application, disable OCSP stapling by setting <tt>{stapling, no_staple}</tt> in the client options, or switch to CRL-based revocation checking with <tt>{crl_check, true}</tt>.</li><li>For applications calling <tt>public_key:pkix_ocsp_validate/5</tt> directly, validate the responder certificate's validity period in application code before calling the function.</li></ul>"
                        }
                    ],
                    "value": "* For TLS clients using the ssl application, disable OCSP stapling by setting {stapling, no_staple} in the client options, or switch to CRL-based revocation checking with {crl_check, true}.\n* For applications calling public_key:pkix_ocsp_validate/5 directly, validate the responder certificate's validity period in application code before calling the function."
                }
            ],
            "x_generator": {
                "engine": "cvelib 1.8.0"
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        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-05-27T15:40:27.647844Z",
                                "id": "CVE-2026-42791",
                                "options": [
                                    {
                                        "Exploitation": "none"
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                                        "Automatable": "no"
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                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
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                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
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                    "dateUpdated": "2026-05-27T15:40:49.123Z"
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}