{"id":"DEBIAN-CVE-2026-33540","details":"Distribution is a toolkit to pack, ship, store, and deliver container content. Prior to 3.1.0, in pull-through cache mode, distribution discovers token auth endpoints by parsing WWW-Authenticate challenges returned by the configured upstream registry. The realm URL from a bearer challenge is used without validating that it matches the upstream registry host. As a result, an attacker-controlled upstream (or an attacker with MitM position to the upstream) can cause distribution to send the configured upstream credentials via basic auth to an attacker-controlled realm URL. This vulnerability is fixed in 3.1.0.","modified":"2026-09-14T17:03:08.226983176Z","published":"2026-04-06T15:17:10.950Z","upstream":["CVE-2026-33540"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-33540"}],"affected":[{"package":{"name":"docker-registry","ecosystem":"Debian:12","purl":"pkg:deb/debian/docker-registry?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.8.2+ds1-1","2.8.3+ds1-1","2.8.3+ds1-2","2.8.3+ds1-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33540.json"}},{"package":{"name":"docker-registry","ecosystem":"Debian:13","purl":"pkg:deb/debian/docker-registry?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.8.3+ds1-2","2.8.3+ds1-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33540.json"}},{"package":{"name":"docker-registry","ecosystem":"Debian:14","purl":"pkg:deb/debian/docker-registry?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.8.3+ds1-3"}]}],"versions":["2.8.3+ds1-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33540.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}