Medium Authentication

CVE-2026-71577 — Multicluster-global-hub: multicluster-global-hub: spec-topic read acl leaks bootstrap kubeconfigs to all managed hubs during migration

A flaw was found in multicluster-global-hub. During a ManagedClusterMigration, the system incorrectly grants all managed hubs read access to a shared communication topic. This allows a compromised managed hub to intercept and collect sensitive bootstrap kubeconfigs, which contain API server tokens intended for other hubs. These tokens have an extended validity of approximately 9.86 years, significantly increasing the risk of unauthorized access and information disclosure to other managed clusters.

Published Aug 10, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: redhat

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

—

No EPSS score.

Affects

Red Hat

Multicluster Global Hub 1.4.9 and 4 more

CVSS base

6.3

Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Red Hat Multicluster Global Hub 1.4.9, Red Hat Multicluster Global Hub 1.5.8, Red Hat Multicluster Global Hub 1.6.6…).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Red Hat	Multicluster Global Hub 1.4.9	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Multicluster Global Hub 1.5.8	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Multicluster Global Hub 1.6.6	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Multicluster Global Hub 1.7.3	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Multicluster Global Hub 1.8.2	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

High

Privileges required

Low

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
6.3	CVSS 3.1	Medium	1.8	4.0	secalert@redhat.com via NIST National Vulnerability Database
6.3	CVSS 3.1	Medium	—	—	redhat via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N (score shown at the top: secalert@redhat.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-522 · Insufficiently Protected Credentials

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.

web/proxy/WAF logsnetwork IDS/IPSauthentication logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · red hat/multicluster global hub 1.4.9, red hat/multicluster global hub 1.5.8, red hat/multicluster global hub 1.6.6, red
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
CVSS changed · 6.3
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Awaiting Analysis
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Aug 10, 2026 · redhat

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

8 on the record

access.redhat.com/errata/RHSA-2026:67842
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2026:73419
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
bugzilla.redhat.com/show_bug.cgi
issue-tracking, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2026:67516
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2026:73038
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/security/cve/CVE-2026-71577
vdb-entry, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2026:68515
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2026:71597
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database

Elsewhere on this site

Red Hat
every CVE for this vendor

Authentication
same class

CWE-522
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-66792 Multicloud-operators-subscription: multicloud-operators-subscription: isclusteradmin() trusts user-settable annotations on managed clusters Aug 17, 2026
High CVE-2026-71576 Multicluster-global-hub: multicluster-global-hub: manager trusts self-asserted evt.source() for leaf-hub identity in all status handlers Aug 10, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No FIRST EPSS score.
No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-71577 is "Multicluster-global-hub: multicluster-global-hub: spec-topic read acl leaks bootstrap kubeconfigs to all managed hubs during migration", rated Medium. It affects Multicluster Global Hub 1.4.9 (Red Hat); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.3 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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