CVE-2026-71403
MediumCVSS 6.1Summary
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.
Risk Assessment
The risk is account takeover and privilege escalation, as an attacker can inject a foreign principal into a victim's account, potentially leading to unauthorized access to resources.
Recommendation
It is recommended to immediately upgrade Rancher to version 2.15.1 or later and to review permissions of users with access to User resource updates.
Other vulnerabilities in Rancher Manager
See all- CVE-2026-75035High
A flaw was found in Rancher Manager. When a non-administrative caller supplied a label selector naming a different user, the ext.cattle.io/v1 Token store dropped its internal owner filter instead of returning an empty result. Any authenticated user could therefore list and watch every other user's tokens, disclosing token metadata and the stored salted hash of the bearer token. This issue affects Rancher before 2.15.1.
- CVE-2026-75034High
A flaw was found in Rancher Manager. The SAML assertion replay protection introduced by the fix for CVE-2026-44946 recorded consumed assertion IDs in a per-process cache, so each replica only detected replays that reached the same pod. In a high-availability deployment, an attacker holding a captured assertion could replay it once against every other replica to obtain additional authenticated sessions as the victim. This issue affects Rancher before 2.15.1.
- CVE-2026-75033High
In Rancher Manager, project secrets were propagated into a namespace based only on the `field.cattle.io/projectId` annotation, without verifying that the project belonged to the same downstream cluster. A user able to create namespaces could set the annotation to a project ID from another cluster and have that project's secrets copied into a namespace under their control.
- CVE-2026-71404High
In Rancher Manager, the GlobalRole controller derived the target ClusterRole name from the user-settable `authz.management.cattle.io/cr-name` annotation and overwrote that object's rules without verifying ownership. A user with delegated GlobalRole create or update permission could point the annotation at any existing ClusterRole, such as `cluster-admin`, and revoke the permissions of every principal bound to it.
- CVE-2026-44939Critical
CVE-2026-44939 describes a command injection vulnerability in the Rancher Manager import endpoint before version 2.14.2, potentially allowing the execution of malicious containers.
Original NVD description (English source)
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.