CVE-2026-71403

EUVD-2026-70501
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 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.


This issue affects Rancher: before 2.15.1.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
suseCNA
6.1 MEDIUM
NETWORK
LOW
HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
suserancher
𝑥
< 2.15.1
CNA
Common Weakness Enumeration
References
https://github.com/rancher/rancher/pull/56616