CVE-2026-71403
Low
No strong exploitation signal.
CVSS base
6.1
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N
EPSS — probability of exploitation (30 days)
0.2%
9.7th percentile
CISA KEV
Not listed
Weakness / dates
CWE-639
Published 2026-09-03 · modified 2026-09-18
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | H | High |
| User Interaction | R | Required |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | N | None |
Timeline
- 2026-09-03 — Published (NVD)
- 2026-09-18 — Last modified (NVD)
Description
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.