{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-65626",
        "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "state": "PUBLISHED",
        "assignerShortName": "EEF",
        "dateReserved": "2026-07-22T13:55:59.401Z",
        "datePublished": "2026-10-26T19:53:05.620Z",
        "dateUpdated": "2026-10-26T19:53:05.620Z"
    },
    "containers": {
        "cna": {
            "affected": [
                {
                    "collectionURL": "https://repo.hex.pm",
                    "cpes": [
                        "cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*"
                    ],
                    "defaultStatus": "unaffected",
                    "modules": [
                        "jose_jwa_pkcs1"
                    ],
                    "packageName": "jose",
                    "packageURL": "pkg:hex/jose",
                    "product": "jose",
                    "programFiles": [
                        "src/jwa/jose_jwa_pkcs1.erl"
                    ],
                    "programRoutines": [
                        {
                            "name": "jose_jwa_pkcs1:decrypt_private/3"
                        },
                        {
                            "name": "jose_jwa_pkcs1:rsaes_pkcs1_decrypt/2"
                        },
                        {
                            "name": "jose_jwa_pkcs1:eme_pkcs1_decode/2"
                        },
                        {
                            "name": "jose_jwa_pkcs1:dp/2"
                        }
                    ],
                    "repo": "https://github.com/potatosalad/erlang-jose",
                    "vendor": "potatosalad",
                    "versions": [
                        {
                            "lessThan": "1.11.13",
                            "status": "affected",
                            "version": "1.3.0",
                            "versionType": "semver"
                        }
                    ]
                },
                {
                    "collectionURL": "https://github.com",
                    "cpes": [
                        "cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*"
                    ],
                    "defaultStatus": "unaffected",
                    "modules": [
                        "jose_jwa_pkcs1"
                    ],
                    "packageName": "potatosalad/erlang-jose",
                    "packageURL": "pkg:github/potatosalad/erlang-jose",
                    "product": "jose",
                    "programFiles": [
                        "src/jwa/jose_jwa_pkcs1.erl"
                    ],
                    "programRoutines": [
                        {
                            "name": "jose_jwa_pkcs1:decrypt_private/3"
                        },
                        {
                            "name": "jose_jwa_pkcs1:rsaes_pkcs1_decrypt/2"
                        },
                        {
                            "name": "jose_jwa_pkcs1:eme_pkcs1_decode/2"
                        },
                        {
                            "name": "jose_jwa_pkcs1:dp/2"
                        }
                    ],
                    "repo": "https://github.com/potatosalad/erlang-jose",
                    "vendor": "potatosalad",
                    "versions": [
                        {
                            "lessThan": "0eac8cef9aaa48fb6846f4e47a0002dc4a73966d",
                            "status": "affected",
                            "version": "853c5d4c4c0bd2a7ecb055b237f4284184e176c8",
                            "versionType": "git"
                        }
                    ]
                }
            ],
            "configurations": [
                {
                    "lang": "en",
                    "supportingMedia": [
                        {
                            "base64": false,
                            "type": "text/html",
                            "value": "<p>The vulnerable code path is only reached when jose performs RSAES-PKCS1-v1_5 decryption with its pure-Erlang fallback (the <code>jose_jwa_pkcs1</code> module) instead of the native OTP <code>public_key</code> implementation. This requires the crypto_fallback option to be enabled (<code>application:set_env(jose, crypto_fallback, true)</code>, or <code>JOSE.crypto_fallback(true)</code> in Elixir) and the OTP runtime not to provide native RSA1_5 decryption. When native OTP RSA support is selected, decryption does not go through <code>jose_jwa_pkcs1</code>.</p>"
                        },
                        {
                            "base64": false,
                            "type": "text/markdown",
                            "value": "The vulnerable code path is only reached when jose performs RSAES-PKCS1-v1_5 decryption with its pure-Erlang fallback (the `jose_jwa_pkcs1` module) instead of the native OTP `public_key` implementation. This requires the crypto_fallback option to be enabled (`application:set_env(jose, crypto_fallback, true)`, or `JOSE.crypto_fallback(true)` in Elixir) and the OTP runtime not to provide native RSA1_5 decryption. When native OTP RSA support is selected, decryption does not go through `jose_jwa_pkcs1`."
                        }
                    ],
                    "value": "The vulnerable code path is only reached when jose performs RSAES-PKCS1-v1_5 decryption with its pure-Erlang fallback (the jose_jwa_pkcs1 module) instead of the native OTP public_key implementation. This requires the crypto_fallback option to be enabled (application:set_env(jose, crypto_fallback, true), or JOSE.crypto_fallback(true) in Elixir) and the OTP runtime not to provide native RSA1_5 decryption. When native OTP RSA support is selected, decryption does not go through jose_jwa_pkcs1."
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "cpeMatch": [
                                {
                                    "criteria": "cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*",
                                    "versionEndExcluding": "1.11.13",
                                    "versionStartIncluding": "1.3.0",
                                    "vulnerable": true
                                }
                            ],
                            "negate": false,
                            "operator": "OR"
                        }
                    ],
                    "operator": "AND"
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "type": "reporter",
                    "value": "Peter Ullrich"
                },
                {
                    "lang": "en",
                    "type": "remediation developer",
                    "value": "Andrew Bennett"
                },
                {
                    "lang": "en",
                    "type": "analyst",
                    "value": "Jonatan Männchen / EEF"
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "supportingMedia": [
                        {
                            "base64": false,
                            "type": "text/html",
                            "value": "<p>The pure-Erlang RSAES-PKCS1-v1_5 decryption in the <code>jose_jwa_pkcs1</code> module is a Bleichenbacher padding oracle. <code>eme_pkcs1_decode/2</code> returns the recovered message when a decrypted block has valid <code>PKCS#1</code> v1.5 padding (a leading <code>0x00 0x02</code>, a padding string of at least eight non-zero bytes, and a <code>0x00</code> separator) and returns a distinct error result otherwise, and <code>rsaes_pkcs1_decrypt/2</code> additionally returns <code>{error, {badsize, _}}</code> when the length check fails. The implementation applies no implicit-rejection countermeasure (RFC 8017 §7.2.2): it does not substitute a deterministic pseudo-random plaintext on a padding failure, so a one-bit padding-conformance signal leaks to the caller. Because the underlying modular exponentiation in <code>dp/2</code> is a raw, non-blinded <code>crypto:mod_pow/3</code>, the padding check also stays distinguishable by timing even when an application normalizes every failure to a single error value.</p>\n<p>An unauthenticated attacker who knows only the public RSA key and can submit ciphertexts to a decryption endpoint that unwraps RSA1_5 JWE keys (or otherwise calls <code>decrypt_private/3</code> with <code>rsa_pkcs1_padding</code>) can use this oracle to recover the plaintext of intercepted ciphertexts, such as content-encryption keys and thus the protected message, or to forge signatures, through roughly 10^4 to 10^6 adaptive chosen-ciphertext queries.</p>\n<p>This issue affects jose: from 1.3.0 before 1.11.13.</p>"
                        },
                        {
                            "base64": false,
                            "type": "text/markdown",
                            "value": "The pure-Erlang RSAES-PKCS1-v1_5 decryption in the `jose_jwa_pkcs1` module is a Bleichenbacher padding oracle. `eme_pkcs1_decode/2` returns the recovered message when a decrypted block has valid `PKCS#1` v1.5 padding (a leading `0x00 0x02`, a padding string of at least eight non-zero bytes, and a `0x00` separator) and returns a distinct error result otherwise, and `rsaes_pkcs1_decrypt/2` additionally returns `{error, {badsize, _}}` when the length check fails. The implementation applies no implicit-rejection countermeasure (RFC 8017 §7.2.2): it does not substitute a deterministic pseudo-random plaintext on a padding failure, so a one-bit padding-conformance signal leaks to the caller. Because the underlying modular exponentiation in `dp/2` is a raw, non-blinded `crypto:mod_pow/3`, the padding check also stays distinguishable by timing even when an application normalizes every failure to a single error value.\n\nAn unauthenticated attacker who knows only the public RSA key and can submit ciphertexts to a decryption endpoint that unwraps RSA1_5 JWE keys (or otherwise calls `decrypt_private/3` with `rsa_pkcs1_padding`) can use this oracle to recover the plaintext of intercepted ciphertexts, such as content-encryption keys and thus the protected message, or to forge signatures, through roughly 10^4 to 10^6 adaptive chosen-ciphertext queries.\n\nThis issue affects jose: from 1.3.0 before 1.11.13."
                        }
                    ],
                    "value": "The pure-Erlang RSAES-PKCS1-v1_5 decryption in the jose_jwa_pkcs1 module is a Bleichenbacher padding oracle. eme_pkcs1_decode/2 returns the recovered message when a decrypted block has valid PKCS#1 v1.5 padding (a leading 0x00 0x02, a padding string of at least eight non-zero bytes, and a 0x00 separator) and returns a distinct error result otherwise, and rsaes_pkcs1_decrypt/2 additionally returns {error, {badsize, _}} when the length check fails. The implementation applies no implicit-rejection countermeasure (RFC 8017 §7.2.2): it does not substitute a deterministic pseudo-random plaintext on a padding failure, so a one-bit padding-conformance signal leaks to the caller. Because the underlying modular exponentiation in dp/2 is a raw, non-blinded crypto:mod_pow/3, the padding check also stays distinguishable by timing even when an application normalizes every failure to a single error value.\n\nAn unauthenticated attacker who knows only the public RSA key and can submit ciphertexts to a decryption endpoint that unwraps RSA1_5 JWE keys (or otherwise calls decrypt_private/3 with rsa_pkcs1_padding) can use this oracle to recover the plaintext of intercepted ciphertexts, such as content-encryption keys and thus the protected message, or to forge signatures, through roughly 10^4 to 10^6 adaptive chosen-ciphertext queries.\n\nThis issue affects jose: from 1.3.0 before 1.11.13."
                }
            ],
            "impacts": [
                {
                    "capecId": "CAPEC-463",
                    "descriptions": [
                        {
                            "lang": "en",
                            "value": "CAPEC-463 Padding Oracle Crypto Attack"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "Automatable": "NOT_DEFINED",
                        "Recovery": "NOT_DEFINED",
                        "Safety": "NOT_DEFINED",
                        "attackComplexity": "LOW",
                        "attackRequirements": "PRESENT",
                        "attackVector": "LOCAL",
                        "baseScore": 5.9,
                        "baseSeverity": "MEDIUM",
                        "privilegesRequired": "NONE",
                        "providerUrgency": "NOT_DEFINED",
                        "subAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "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:N/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-203",
                            "description": "CWE-203 Observable Discrepancy",
                            "lang": "en",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
                "shortName": "EEF",
                "dateUpdated": "2026-10-26T19:53:05.620Z"
            },
            "references": [
                {
                    "tags": [
                        "vendor-advisory",
                        "related"
                    ],
                    "url": "https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-vwvr-f994-6j9j"
                },
                {
                    "name": "EEF CNA record for CVE-2026-65626",
                    "tags": [
                        "related"
                    ],
                    "url": "https://cna.erlef.org/cves/CVE-2026-65626.html"
                },
                {
                    "name": "OSV record EEF-CVE-2026-65626",
                    "tags": [
                        "related"
                    ],
                    "url": "https://osv.dev/vulnerability/EEF-CVE-2026-65626"
                },
                {
                    "name": "Introducing commit 853c5d4 in potatosalad/erlang-jose",
                    "tags": [
                        "related"
                    ],
                    "url": "https://github.com/potatosalad/erlang-jose/commit/853c5d4c4c0bd2a7ecb055b237f4284184e176c8"
                },
                {
                    "name": "Fix commit 0eac8ce in potatosalad/erlang-jose",
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/potatosalad/erlang-jose/commit/0eac8cef9aaa48fb6846f4e47a0002dc4a73966d"
                }
            ],
            "source": {
                "discovery": "EXTERNAL"
            },
            "title": "Bleichenbacher padding oracle in RSAES-PKCS1-v1_5 decryption in jose"
        }
    }
}