CVE-2026-49824: Fission: Cross-namespace Environment reference via unvalidated EnvironmentRef in Function admission webhook

Vulnerability summary

CVE-2026-49824 is a high (CVSS 8.5) Improper Access Control vulnerability in fission. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.7% of scored vulnerabilities.

Timeline

1. 10-06-2026
   PublishedVulnerability first disclosed.
2. 10-06-2026
   Last modifiedVulnerability information updated.

Description

Fission is an open-source, Kubernetes-native serverless framework that simplifies the deployment of functions and applications on Kubernetes. Prior to version 1.24.0, the Fission Function admission webhook (pkg/webhook/function.go) validated that spec.secrets[].namespace and spec.configmaps[].namespace equalled the function's own namespace but performed no equivalent check on spec.environment.namespace. This issue has been patched in version 1.24.0.

• CWE-284Improper Access ControlThe product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
• CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.