Privilege escalation in downstream clusters via GlobalRole inheritedNamespacedRules
Affects Rancher 2.15.0 and later, where a delegated authenticated user can gain permissions in downstream cluster namespaces beyond their own. Fixed in Rancher 2.15.3, which uses rancher-webhook v0.11.4.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 2.15.3, 0.11.4, 0.12.1
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Rancher v2.15.0 and later are affected. The attacker must be an authenticated Rancher user who has been delegated the ability to create or update management.cattle.io globalroles and to create globalrolebindings.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 26/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Fix
- Fixed in 2.15.3, 0.11.4, 0.12.1
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
SUSE Rancher Manager and the SUSE Rancher Webhook are affected. A flaw in how global role permissions are validated could let a non-administrative user gain permissions in downstream clusters beyond what they already hold.
Read the original description
A privilege escalation issue was discovered in Rancher Manager's role-based access control. The inheritedNamespacedRules field of a GlobalRole propagates permissions into named namespaces of every downstream cluster managed by the Rancher instance, but it was not subject to the privilege-escalation validation applied to the other permission-carrying fields of a GlobalRole. As a result, a non-administrative user could be granted, through a global role binding, permissions in downstream clusters that exceed the permissions that user already holds. This affected SUSE Rancher 2.15.2 only, and SUSE Rancher Webhook 0.11.0 up to 0.11.4, and 0.12.0 up to 0.12.1.
What to do
Check whether your setup matches what the bug needs.
Rancher v2.15.0 and later are affected. The attacker must be an authenticated Rancher user who has been delegated the ability to create or update management.cattle.io globalroles and to create globalrolebindings.Upgrade to a fixed version: 2.15.3, 0.11.4, 0.12.1.
Workaround: Restrict custom global roles that delegate create or update on management.cattle.io globalroles and create on globalrolebindings to trusted administrators, and audit existing inheritedNamespacedRules entries and GlobalRoleBinding objects.
Timeline
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- CVE published
- First seen by cve.now1 day
- Record last updated
Affected versions
- Rancher
From 2.15.2 · fixed in 2.15.3
- Webhook
From 0.11.0 · fixed in 0.11.4; From 0.12.0 · fixed in 0.12.1
Evidence 1
- Advisory
Corrections
None so far.
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Questions about CVE-2026-88810
What does this mean?
A user who has been delegated the ability to create or update management.cattle.io globalroles and to create globalrolebindings could gain permissions in namespaces of downstream clusters that exceed their own. The impact can extend to confidentiality, integrity, and availability of resources in the targeted namespaces across all managed downstream clusters.Source: github.com
Am I affected, and how do I check?
Rancher v2.15.0 and later are affected, and the relevant user must already hold the delegated ability to create or update GlobalRoles and create GlobalRoleBindings. To check, look at the installed Rancher version and review any custom global roles that grant those permissions, including existing inheritedNamespacedRules entries.Source: github.com
What should I do about it?
Upgrade Rancher to v2.15.3, which ships rancher-webhook v0.11.4. If you cannot upgrade yet, restrict custom global roles that delegate those permissions to trusted administrators and audit existing inheritedNamespacedRules entries and GlobalRoleBinding objects.Source: github.com
Is it being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data