# CVE-2026-50545: Fission PodSpec injection leading to node escape in Environment CRD

Source: https://junglewise.ai/threats/cve-2026-50545-fission-podspec-injection-leading-to-node-escape-in-environment  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-10. Updated: 2026-06-30  
License: CC BY 4.0 with a link back

CVE-2026-50545 · Severity: critical · CVSS 9.9 · Published 2026-06-10

Fission, a serverless framework for Kubernetes, contains a vulnerability where users with basic permissions can bypass security checks to run highly privileged code. By injecting malicious configurations into the environment settings, an attacker can escape the isolated container and gain full control over the underlying server infrastructure. This could lead to the theft of sensitive cluster credentials and a complete takeover of the entire Kubernetes environment.

Technologies: [Fission](https://junglewise.ai/threats/technologies/fission), [github.com/fission/fission (Go)](https://junglewise.ai/threats/technologies/github-com-fission-fission). Vendors: [Fission](https://junglewise.ai/threats/vendors/fission), [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-50545 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-50545 being exploited in the wild.

**How severe is CVE-2026-50545?** Critical severity, with a CVSS score of 9.9, published 10 June 2026.

**Which products and versions are affected?** Fission < 1.24.0, <= 1.23.0; github.com/fission/fission (Go) <= 1.23.0, SEMVER:introduced=0,fixed=1.24.0.

**Is there a fix for CVE-2026-50545?** Yes. github.com/fission/fission (Go): upgrade to 1.24.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-50545 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-50545?** Check whether you run Fission or github.com/fission/fission (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/fission/fission (Go): upgrade to 1.24.0 or later

  ```sh
  go get github.com/fission/fission@v1.24.0
  ```


## Technical details

A critical vulnerability exists in Fission due to three compounding flaws in the handling of Environment Custom Resource Definitions (CRDs). First, the validation logic in `pkg/apis/core/v1/validation.go` failed to check for dangerous PodSpec fields such as `hostPID`, `hostIPC`, `hostNetwork`, and `privileged`. Second, the admission webhook only monitored 'create' operations, allowing attackers to bypass checks by patching existing environments. Finally, the `MergePodSpec` function unconditionally propagated these dangerous fields into generated deployments. An attacker with basic RBAC permissions to create or update environments can schedule a privileged pod with host-root mounts, enabling them to read the cluster CA private key and achieve full cluster takeover. The issue is fixed in version 1.24.0.

## Affected products

- fission fission <= 1.23.0

## Identifiers

- CVE-2026-50545
- GHSA-wmgg-3p4h-48x7
- GO-2026-5860

## Timeline

- 2026-05-26: disclosed
- 2026-06-10: advisory: NVD publication date
- 2026-06-30: patched: GitHub Advisory published/updated with fix details

## References

- [https://api.github.com/users/j311yl0v3u](https://api.github.com/users/j311yl0v3u)
- [https://github.com/j311yl0v3u](https://github.com/j311yl0v3u)
- [https://api.github.com/users/j311yl0v3u/gists%7B/gist_id%7D](https://api.github.com/users/j311yl0v3u/gists%7B/gist_id%7D)
- [https://api.github.com/users/j311yl0v3u/repos](https://api.github.com/users/j311yl0v3u/repos)
- [https://avatars.githubusercontent.com/u/102125416?v=4](https://avatars.githubusercontent.com/u/102125416?v=4)
- [https://api.github.com/users/j311yl0v3u/events%7B/privacy%7D](https://api.github.com/users/j311yl0v3u/events%7B/privacy%7D)

## Related threats

- [GO-2026-5849 - Fission: MessageQueueTrigger scaler manager materializes Secret values into Deployment envvars and accepts arbitrary user PodSpec in github.](https://junglewise.ai/threats/go-2026-5849-fission-messagequeuetrigger-scaler-manager-materializes-509f5f41)
- [Fission privilege escalation in MessageQueueTrigger scaler manager](https://junglewise.ai/threats/fission-privilege-escalation-in-messagequeuetrigger-scaler-manager-7fe266a4)
- [Fission incomplete capability denylist in Environment and Function CRDs](https://junglewise.ai/threats/cve-2026-50570-fission-incomplete-capability-denylist-in-environment-and)
- [Fission HTTPTrigger improper input validation in RelativeURL and Prefix](https://junglewise.ai/threats/cve-2026-50569-fission-httptrigger-improper-input-validation-in-relativeurl-and)
- [Fission path traversal in SanitizeFilePath utility](https://junglewise.ai/threats/cve-2026-50568-fission-path-traversal-in-sanitizefilepath-utility)