---
title: "CVE-2026-50566: Fission: Environment Runtime.Container and Builder.Container SecurityContext bypass allows privileged pod creation"
url: https://erroneo.us/security/cve/CVE-2026-50566/
description: "CVE-2026-50566 (github.com/fission/fission (Go)): Fission is an open-source, Kubernetes-native serverless framework that simplifies the deployment of…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-06-10
date_modified: 2026-06-30
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-50566"
kev: false
cvss: 9.9
epss: 0.00506
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-50566: Fission: Environment Runtime.Container and Builder.Container SecurityContext bypass allows privileged pod creation

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.5% , percentile 42: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 42% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes github.com/fission/fission (Go) <= 1.23.0, fixed in 1.24.0 . Check your lockfile, including transitive dependencies.

## What it is

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, a tenant with environments.fission.io create/update RBAC can run privileged / allowPrivilegeEscalation / dangerous-capability containers in the Fission function or builder namespace, scheduled under the executor's high-privilege service account — enabling container-sandbox escape, host filesystem and network access, and potential node- and cluster-level compromise. This issue has been patched in version 1.24.0.

## Affected packages

- Go `github.com/fission/fission` <= 1.23.0 → fixed: 1.24.0

## Affected products (CVE record)

- fission fission: < 1.24.0

## Severity

- GitHub_M CVSS 3.1: 9.9 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.9 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.51% probability of exploitation activity in the next 30 days; percentile 42.

## Sources

- [GitHub Advisory GHSA-m63v-2g9w-2w6v](https://github.com/advisories/GHSA-m63v-2g9w-2w6v)
- [CVE.org record CVE-2026-50566](https://www.cve.org/CVERecord?id=CVE-2026-50566)
- [NVD entry CVE-2026-50566](https://nvd.nist.gov/vuln/detail/CVE-2026-50566)
- [github.com](https://github.com/fission/fission/security/advisories/GHSA-m63v-2g9w-2w6v)
- [github.com](https://github.com/fission/fission/pull/3406)
- [github.com](https://github.com/fission/fission/releases/tag/v1.24.0)
- [github.com](https://github.com/fission/fission/commit/695d3e97e3a20463ab7c8c081843e69e65e952e5)

---
Source page: https://erroneo.us/security/cve/CVE-2026-50566/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt