CVE-2026-61795
Capsule: hostnameRegexHandler.OnUpdate validates stale (old) Tenant regex, allowing invalid AllowedHostnames regex to bypass webhook validation
Capsule is a multi-tenancy and policy-based framework for Kubernetes. From 0.13.0 until 0.13.7, hostnameRegexHandler.OnUpdate in internal/webhook/tenant/validation/hostname_regex.go reverses the new and old Tenant parameters and validates the previous AllowedHostnames.Regex instead of the submitted value. A cluster administrator can therefore store a malformed AllowedHostnames.Regex after the webhook accepts the update based on stale valid state. Subsequent Ingress creation or update reaches validate_hostnames.go, which evaluates the malformed pattern, ignores the regular-expression error, and treats every hostname as unmatched, blocking Ingress operations for the affected tenant until an administrator repairs the Tenant configuration. This issue is fixed in version 0.13.7.
- Affected
- projectcapsule · capsule
- CVSS v3.1 GITHUB
- 6.8 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H - EPSS
- 0.59% chance of exploitation in the next 30 days, 47th percentile
- Published
- 2026-09-18
- Updated
- 2026-09-21