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CVE-2026-15806 on Cyberus Linux 26.05

Aliases: CVE-2026-15806

Packages: python311, python312, python313, python314, python315

Status: Plausible

Advisory Information

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.

Updates

2026-08-26 10:53 CEST

Metadata changes:

  • Status for package python311: “Plausible”
  • Status for package python312: “Plausible”
  • Status for package python313: “Plausible”
  • Status for package python314: “Plausible”
  • Status for package python315: “Plausible”

2026-08-26 10:09 CEST

Metadata changes:

  • Status for package python311: “New”
  • Status for package python312: “New”
  • Status for package python313: “New”
  • Status for package python314: “New”
  • Status for package python315: “New”