Vulnerability · Published Jul 30, 2026 · Assigned by GitHub_M

CVE-2026-65834Capsule: CapsuleConfiguration NodeMetadata regex fields lack webhook validation, allowing MustCompile panic on all Node admission requests

Medium 6.8

In plain English

A medium-severity improper input validation in capsule from projectcapsule. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.8Medium

Exploit odds (30 days)0.3%top 74.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Capsule is a multi-tenancy and policy-based framework for Kubernetes. Prior to 0.13.8, CapsuleConfiguration.Spec.NodeMetadata.ForbiddenLabels.Regex and CapsuleConfiguration.Spec.NodeMetadata.ForbiddenAnnotations.Regex were not validated by the configuration admission webhook, allowing a Cluster Admin to store a malformed regex that later reached regexp.MustCompile in pkg/api/forbidden_list.go through internal/webhook/node/user_metadata.go and crashed the node admission webhook on Node create, update, or patch requests. This issue is fixed in version 0.13.8.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/projectcapsule/capsule	0.13.8	GHSA-68cj-mvg9-rgm2
Go	github.com/projectcapsule/capsule	0.13.8	GO-2026-6155

Affected products (as reported)

Vendor	Product	Versions
projectcapsule	capsule	< 0.13.8

Weakness: CWE-20, CWE-248 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H

References

https://github.com/projectcapsule/capsule/security/advisories/GHSA-68cj-mvg9-rgm2 x_refsource_CONFIRM
https://github.com/projectcapsule/capsule/releases/tag/v0.13.8 x_refsource_MISC