Rancher: Identity-field mutation in /v3/users allows account hijack via principal rebind (CVE-2026-71403) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-71403

Rancher: Identity-field mutation in /v3/users allows account hijack via principal rebind

Answer in brief

CVE-2026-71403 records a Unknown severity vulnerability in Rancher: Identity-field mutation in /v3/users allows account hijack via principal rebind. The current sources do not mark it as known exploited. The current feed maps SUSE/Rancher (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 3, 2026Updated Sep 3, 2026Source checked Sep 3, 2026First seen by HOL Sep 3, 2026Material review Sep 3, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps SUSE/Rancher (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
SUSE/Ranchergeneric	>=0 <2.15.1	2.15.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for SUSE/Rancher.
Review the reported fix. Update SUSE/Rancher to 2.15.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 3, 2026

Sources and claim methodology

GitHub security advisorygithub.com

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.