# CVE-2026-50563: Fission Container Executor privilege escalation via PodSpec injection

Source: https://junglewise.ai/threats/cve-2026-50563-fission-container-executor-privilege-escalation-via-podspec  
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-2026-50563 · Severity: critical · CVSS 9.9 · Published 2026-06-10

Fission is a framework for running serverless functions on Kubernetes. A vulnerability in how it handles function configurations allows a user with basic permissions to bypass security restrictions and run highly privileged code. This could allow an attacker to gain full control over the underlying server (node escape), potentially leading to the theft of sensitive data or a complete compromise of the cloud infrastructure.

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-2026-50563 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-50563 being exploited in the wild.

**How severe is CVE-2026-50563?** Critical severity, with a CVSS score of 9.9, published 10 June 2026.

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

**Is there a fix for CVE-2026-50563?** 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-2026-50563 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-50563?** 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 vulnerability exists in Fission's Container Executor where the 'Function.spec.podspec' field is not properly validated or sanitized. Specifically, 'pkg/apis/core/v1/validation.go' fails to inspect the content of the PodSpec, and 'pkg/executor/util/merge.go' unconditionally forwards sensitive fields like 'hostPID', 'hostNetwork', and 'privileged' into the final Deployment. An attacker with 'functions.fission.io/create' permissions can submit a crafted PodSpec to mount the host root filesystem or share host namespaces. Because the executor runs with high privileges, it creates these malicious deployments on behalf of the user, leading to a container breakout and node escape. This is fixed in version 1.24.0 by implementing 'ValidatePodSpecSafety'.

## Affected products

- fission fission <= 1.23.0

## Identifiers

- CVE-2026-50563
- GHSA-v455-mv2v-5g92
- GO-2026-5858

## Timeline

- 2026-05-26: disclosed
- 2026-06-10: advisory: NVD publication date
- 2026-06-30: patched: GitHub Advisory reviewed and updated

## 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)