CVE-2026-71403CWE-639

CVE-2026-71403

Medium · published September 3, 2026

CVSS v3.1
6.1
EPSS
0%
Percentile
29.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.1 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00369 · 29.5th percentile
Weakness
CWE-639 · Authorization Bypass Through User-Controlled Key
Published
2026-09-03T19:17Z
Affected products (1)
ProductVersionsFixed in
suse/rancher< 2.15.12.15.1
References (1)
https://github.com/rancher/rancher/pull/56616 · [email protected]
EPSS history
Timeline
  • 05 SEP 03:44Z
    EPSS moved — → 0%
    epss
  • 03 SEP 14:45Z
    Rancher: Identity-field mutation in /v3/users allows account hijack via principal rebind
    cvelistv5