Critical severity · published May 14, 2026
CVE-2026-42457
vCluster Platform: Stored XSS can lead to privilege escalation
9.0
CVSS
0.3%
EPSS
No
On KEV
Description
vCluster Platform provides a Kubernetes platform for managing virtual clusters, multi-tenancy, and cluster sharing. Prior to 4.4.3, 4.5.5, 4.6.2, 4.7.1, and 4.8.0, there is a Stored XSS attack vulnerability via the name field of a templateRef. This can lead to the execution of arbitrary external scripts within the platform's browser context. In the worst case, a malicious user could potentially create a new Global-Admin user, bypassing other security restrictions. The attacker needs the ability to create namespaces. This vulnerability is fixed in 4.4.3, 4.5.5, 4.6.2, 4.7.1, and 4.8.0.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 24% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LO
loft · loft-sh
< 4.4.3; >=4.5.0-alpha.0 , < 4.5.5; >= 4.6.0-alpha.1, < 4.6.2; >= 4.7.0-alpha.0, < 4.7.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42457
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42457
github.com
https://github.com/loft-sh/loft/security/advisories/GHSA-x7cq-v3h6-426c
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