Improper input validation in Fission
CVE-2026-50569
Fission is an open-source, Kubernetes-native serverless framework that simplifies the deployment of functions and applications on Kubernetes. Prior to version 1.25.0, HTTPTriggerSpec.Validate() validated Methods, FunctionReference, Host, IngressConfig, and CorsConfig, but silently skipped RelativeURL and Prefix. Those two fields were validated at the CLI level only (pkg/fission-cli/cmd/httptrigger/create.go:83). The post-CRD-modernization webhook for HTTPTrigger was retired in favor of API-server CEL — and CEL had no rules on those fields either — so an HTTPTrigger created via kubectl apply or a direct Kubernetes REST API call bypassed every URL-level check. This issue has been patched in version 1.25.0.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.002 (13.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
Affected products
- Fission — versions < 1.25.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_CONFIRM)
Frequently asked questions
- What is CVE-2026-50569?
- CVE-2026-50569 is a medium-severity vulnerability in Fission, classified under Improper Input Validation. CVSS score: 4.3/10. Published 2026-06-10.
- How severe is CVE-2026-50569?
- Medium severity. CVSS v3 base score is 4.3 out of 10.