{"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": "2026-08-18T18:07:31.778Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "CPython", "repo": "https://github.com/python/cpython", "vendor": "Python Software Foundation", "versions": [{"version": "0", "lessThan": "3.15.0", "status": "affected", "versionType": "python"}]}], "credits": [{"lang": "en", "type": "reporter", "value": "\u0141ukasz (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. 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{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "CPython", "repo": "https://github.com/python/cpython", "vendor": "Python Software Foundation", "versions": [{"lessThan": "3.15.0", "status": "affected", "version": "0", "versionType": "python"}]}], "source": "cna@python.org"}], "cveTags": [], "descriptions": [{"lang": "en", "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."}], "id": "CVE-2026-15806", "lastModified": "2026-08-18T18:17:26.223", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.0, "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": "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/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": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "cna@python.org", "type": "Secondary"}]}, "published": "2026-08-18T16:17:02.220", "references": [{"source": "cna@python.org", "url": "https://github.com/python/cpython/commit/a0d023fbd23773e24b35d8368789470e22cda5d8"}, {"source": "cna@python.org", "url": "https://github.com/python/cpython/commit/a2773a34183b7d94a243bb98fd658926cc5348ce"}, {"source": "cna@python.org", "url": "https://github.com/python/cpython/commit/a7bb524fef61f77ede01f660ffbd591e1d5837ce"}, {"source": "cna@python.org", "url": "https://github.com/python/cpython/issues/155694"}, {"source": "cna@python.org", "url": "https://github.com/python/cpython/pull/155696"}, {"source": "cna@python.org", "url": "https://mail.python.org/archives/list/security-announce@python.org/thread/3OKPE5S75KDNA7FY7AI3PL2MXM2X5RB3/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "http://www.openwall.com/lists/oss-security/2026/08/18/3"}], "sourceIdentifier": "cna@python.org", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-319"}, {"lang": "en", "value": "CWE-522"}], "source": "cna@python.org", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,3.16.0)"}}], "enrichment": {"confidence": 95.0, "confidence_source": "inferred", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "CPython", "source": "cna", "vendor": "Python Software Foundation"}, "product": "cpython", "vendor": "python"}], "created": "2026-08-18T17:30:15.393989+00:00", "updated": "2026-08-18T17:30:15.508138+00:00", "vendors": ["python", "python$PRODUCT$cpython"]}