{"id":"CVE-2026-71403","title":"A flaw was found in Rancher Manager","summary":"A flaw was found in Rancher Manager. The /v3/users update path did not enforce immutability of a User resource's `username` and `principalIds` fields. A user holding the `update` verb on `users.management.cattle.io` could inject a foreig…","severity":"medium","cvss":6.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N","cwe":["CWE-639"],"vendor":"suse","product":"rancher","affected":["rancher < 2.15.1"],"patched":["rancher 2.15.1"],"published":"2026-09-03","updated":"2026-09-18","sourceUpdated":"2026-09-18T15:03:02.433","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-71403","references":[{"url":"https://github.com/rancher/rancher/pull/56616","label":"meissner@suse.de"}],"tags":["nvd"],"epss":0.00208,"epssPercentile":0.11238,"ingestedAt":"2026-09-08T20:10:03.160Z","slug":"CVE-2026-71403","body":"## Overview\n\nA flaw was found in Rancher Manager. The /v3/users update path did not enforce immutability of a User resource's `username` and `principalIds` fields. A user holding the `update` verb on `users.management.cattle.io` could inject a foreign identity provider principal into any account, so that the next login by the owner of that principal was bound to the victim's account and inherited its role bindings.\n\n\nThis issue affects Rancher: before 2.15.1.\n\n## Affected\n\n- `rancher < 2.15.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `rancher 2.15.1`","depth":"sunlit","depthScore":34,"depthScoreParts":{"impact":33.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}