CVE-2026-100707: Kyverno before 1.19.1 Namespace Isolation Bypass via Percent-Encoded Path

Vulnerability summary

CVE-2026-100707 is a high (CVSS 8.3) vulnerability in kyverno. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 39.9% of scored vulnerabilities.

Timeline

1. 26-09-2026
   PublishedVulnerability first disclosed.
2. 28-09-2026
   Last modifiedVulnerability information updated.

Description

Kyverno before 1.19.1 contains a namespace isolation bypass in the apiCall context entry of namespaced Policy resources due to inconsistent path interpretation between validation and execution. A low-privilege tenant can use percent-encoded dot-segments in urlPath to bypass namespace checks and read resources from other namespaces using the Kyverno admission controller's ServiceAccount credentials.

• CWE-22Improper Limitation of a Pathname to a Restricted DirectoryThe product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.