CVE-2026-71403
Rancher: Identity-field mutation in /v3/users allows account hijack via principal rebind
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Rancher: Identity-field mutation in /v3/users allows account hijack via principal rebind
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.
- Record
CVE-2026-71403- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-639
- Updated
- 2026-11-02
EUVDEUVD-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.
- Record
EUVD-2026-70501- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-71403- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-639
- Updated
- 2026-11-02
OSV
Rancher: Identity-field mutation in /v3/users allows account hijack via principal rebind
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.
- Record
CVE-2026-71403- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-639
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-71403 is a medium vulnerability (CVSS 6.1) in Suse Rancher, published September 3, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.37%, the 30th percentile. No source names a fixed version.