CVE-2026-15806
- Source
- https://cve.org/CVERecord?id=CVE-2026-15806
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-15806.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-15806
- Aliases
- Downstream
- Published
- 2026-08-18T15:50:57.983Z
- Modified
- 2026-08-20T11:47:19.239670147Z
- Severity
-
- 6.0 (Medium) CVSS_V4 - 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 CVSS Calculator
- Summary
- `HTTPPasswordMgr` can send saved HTTPS credentials via HTTP because of incorrect scheme matching
- Details
-
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://.
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.
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.
- Database specific
{ "unresolved_ranges": [ { "extracted_events": [ { "fixed": "3.15.0" } ], "source": "AFFECTED_FIELD" } ], "cna_assigner": "PSF", "cwe_ids": [ "CWE-319", "CWE-522" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/15xxx/CVE-2026-15806.json" }- References
-
- http://www.openwall.com/lists/oss-security/2026/08/18/3
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/15xxx/CVE-2026-15806.json
- https://mail.python.org/archives/list/security-announce@python.org/thread/3OKPE5S75KDNA7FY7AI3PL2MXM2X5RB3/
- https://nvd.nist.gov/vuln/detail/CVE-2026-15806
- https://github.com/python/cpython/issues/155694
- https://github.com/python/cpython/commit/641be42bb07921ba0f8bffe228b1dc706b092ef6
- https://github.com/python/cpython/commit/a0d023fbd23773e24b35d8368789470e22cda5d8
- https://github.com/python/cpython/commit/a2773a34183b7d94a243bb98fd658926cc5348ce
- https://github.com/python/cpython/commit/a7bb524fef61f77ede01f660ffbd591e1d5837ce
- https://github.com/python/cpython/pull/155696
- https://github.com/python/cpython