{"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":"2026-10-02T00:39:20.429Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"CPython","repo":"https://github.com/python/cpython","vendor":"Python Software Foundation","versions":[{"version":"0","lessThan":"3.10.22","status":"affected","versionType":"python"},{"version":"3.11.0","lessThan":"3.11.17","status":"affected","versionType":"python"},{"version":"3.12.0","lessThan":"3.12.15","status":"affected","versionType":"python"},{"version":"3.13.0","lessThan":"3.13.16","status":"affected","versionType":"python"},{"version":"3.14.0","lessThan":"3.14.8","status":"affected","versionType":"python"},{"version":"3.15.0a1","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":"2026-10-02T00:39:20.429Z"},"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"},{"tags":["patch"],"url":"https://github.com/python/cpython/commit/95355ee3a8e1d3c3d4858d1973aa42a9b91a2801"},{"tags":["patch"],"url":"https://github.com/python/cpython/commit/dac88d8615078c55f1304ea4c7a2d822700d4e5a"}],"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"}}]}}