{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-15806",
        "assignerOrgId": "28c92f92-d60d-412d-b760-e73465c3df22",
        "state": "PUBLISHED",
        "assignerShortName": "PSF",
        "dateReserved": "2026-07-15T08:49:13.390Z",
        "datePublished": "2026-08-18T15:50:57.983Z",
        "dateUpdated": "2026-09-02T00:38:15.504Z"
    },
    "containers": {
        "cna": {
            "affected": [
                {
                    "defaultStatus": "unaffected",
                    "product": "CPython",
                    "repo": "https://github.com/python/cpython",
                    "vendor": "Python Software Foundation",
                    "versions": [
                        {
                            "version": "0",
                            "lessThan": "3.15.0rc2",
                            "status": "affected",
                            "versionType": "python"
                        }
                    ]
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "type": "reporter",
                    "value": "Łukasz (https://github.com/lkk7)"
                },
                {
                    "lang": "en",
                    "type": "coordinator",
                    "value": "Kirill Podoprigora (https://github.com/Eclips4)"
                },
                {
                    "lang": "en",
                    "type": "analyst",
                    "value": "Senthil Kumaran (https://github.com/orsenthil)"
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "supportingMedia": [
                        {
                            "type": "text/html",
                            "value": "The HTTPPasswordMgr class in the urllib.request module, along with its subclasses HTTPPasswordMgrWithDefaultRealm and HTTPPasswordMgrWithPriorAuth, did not take the URL scheme into account when matching stored credentials against a requested URL. Credentials added for an https:// URL were also used for requests to the same host over http://, so an attacker able to redirect or downgrade a client to plain HTTP (for example, via an HTTPS-to-HTTP redirect or an on-path position) could capture credentials in cleartext. Credentials added for http:// URLs could likewise be sent over https://.<br><br>Credential matching is now scoped by URL scheme. Credentials registered with a URL that includes a scheme are only used for requests with the same scheme. Credentials registered with a bare authority (such as example.com or example.com:8080) continue to match any scheme, preserving compatibility with existing code, including proxy authentication.<br><br>Users who cannot upgrade immediately can mitigate by ensuring that applications never make plain http:// requests to hosts for which credentials are registered, for example by not following redirects to http:// URLs."
                        }
                    ],
                    "value": "The HTTPPasswordMgr class in the urllib.request module, along with its subclasses HTTPPasswordMgrWithDefaultRealm and HTTPPasswordMgrWithPriorAuth, did not take the URL scheme into account when matching stored credentials against a requested URL. Credentials added for an https:// URL were also used for requests to the same host over http://, so an attacker able to redirect or downgrade a client to plain HTTP (for example, via an HTTPS-to-HTTP redirect or an on-path position) could capture credentials in cleartext. Credentials added for http:// URLs could likewise be sent over https://.\n\nCredential matching is now scoped by URL scheme. Credentials registered with a URL that includes a scheme are only used for requests with the same scheme. Credentials registered with a bare authority (such as example.com or example.com:8080) continue to match any scheme, preserving compatibility with existing code, including proxy authentication.\n\nUsers who cannot upgrade immediately can mitigate by ensuring that applications never make plain http:// requests to hosts for which credentials are registered, for example by not following redirects to http:// URLs."
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "Automatable": "NOT_DEFINED",
                        "Recovery": "NOT_DEFINED",
                        "Safety": "NOT_DEFINED",
                        "attackComplexity": "HIGH",
                        "attackRequirements": "PRESENT",
                        "attackVector": "NETWORK",
                        "baseScore": 6,
                        "baseSeverity": "MEDIUM",
                        "exploitMaturity": "NOT_DEFINED",
                        "privilegesRequired": "NONE",
                        "providerUrgency": "NOT_DEFINED",
                        "subAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "userInteraction": "PASSIVE",
                        "valueDensity": "NOT_DEFINED",
                        "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/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-319",
                            "description": "CWE-319",
                            "lang": "en",
                            "type": "CWE"
                        },
                        {
                            "cweId": "CWE-522",
                            "description": "CWE-522",
                            "lang": "en",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "28c92f92-d60d-412d-b760-e73465c3df22",
                "shortName": "PSF",
                "dateUpdated": "2026-09-02T00:38:15.504Z"
            },
            "references": [
                {
                    "tags": [
                        "issue-tracking"
                    ],
                    "url": "https://github.com/python/cpython/issues/155694"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/pull/155696"
                },
                {
                    "tags": [
                        "vendor-advisory"
                    ],
                    "url": "https://mail.python.org/archives/list/security-announce@python.org/thread/3OKPE5S75KDNA7FY7AI3PL2MXM2X5RB3/"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/a0d023fbd23773e24b35d8368789470e22cda5d8"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/a2773a34183b7d94a243bb98fd658926cc5348ce"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/a7bb524fef61f77ede01f660ffbd591e1d5837ce"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/641be42bb07921ba0f8bffe228b1dc706b092ef6"
                },
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/python/cpython/commit/851cf9a7142ecbdd39f831055533f58284ad2bcc"
                }
            ],
            "source": {
                "discovery": "UNKNOWN"
            },
            "title": "`HTTPPasswordMgr` can send saved HTTPS credentials via HTTP because of incorrect scheme matching",
            "x_generator": {
                "engine": "cvelib 1.8.0"
            }
        },
        "adp": [
            {
                "title": "CVE Program Container",
                "references": [
                    {
                        "url": "http://www.openwall.com/lists/oss-security/2026/08/18/3"
                    }
                ],
                "providerMetadata": {
                    "orgId": "af854a3a-2127-422b-91ae-364da2661108",
                    "shortName": "CVE",
                    "dateUpdated": "2026-08-18T18:07:31.778Z"
                }
            },
            {
                "references": [
                    {
                        "url": "https://github.com/python/cpython/issues/155694",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-08-18T18:56:36.349726Z",
                                "id": "CVE-2026-15806",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-08-18T18:56:57.585Z"
                }
            }
        ]
    }
}