# CVE-2026-46618: Fission builder accepts arbitrary buildcmd strings from Environment.spec.builder.command, allowing the builder pod to invoke arbitrary executables

> Attackers with Environment CRD access can inject arbitrary commands into Fission builder pods, leading to remote code execution and privilege escalation.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Jun 2026
- **Updated:** 10 Jun 2026
- **Also known as:** GHSA-7pjr-qpvh-m339, GO-2026-5230

## What is CVE-2026-46618?

CVE-2026-46618 is a medium-severity command injection vulnerability in fission, published on 10 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Fission is an open-source, Kubernetes-native serverless framework that simplifies the deployment of functions and applications on Kubernetes. Prior to version 1.23.0, before the round-1 security sweep, pkg/builder/builder.go passed Environment.spec.builder.command directly into exec.Command(...) after a strings.Fields split, with no validation of the executable path or its arguments. A user who could create or update Environment CRDs in a namespace observed by the buildermgr could thereby point the builder pod at any executable inside the builder image (e.g. /bin/sh -c '...') and execute arbitrary code in the builder pod context. This issue has been patched in version 1.23.0.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command), CWE-269 (Improper Privilege Management), CWE-250 (Execution with Unnecessary Privileges)

## Which versions are affected by CVE-2026-46618?

3 open source packages ship an affected version, including github.com/fission/fission.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/fission/fission` | Go | All versions | 1.23.0 |
| `github.com/fission/fission` | Go | All versions | 1.23.0 |
| `github.com/fission/fission` | Go | All versions | 1.23.0 |

## How do I fix CVE-2026-46618?

Upgrade github.com/fission/fission to 1.23.0 or later.

## Is CVE-2026-46618 being exploited?

There is no known exploitation of CVE-2026-46618 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46618 and fix it if it is affected.

What it is: CVE-2026-46618 is a medium-severity command injection vulnerability in fission, published on 10 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-46618 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/fission/fission (Go): affected all versions; fixed in 1.23.0
- github.com/fission/fission (Go): affected all versions; fixed in 1.23.0
- github.com/fission/fission (Go): affected all versions; fixed in 1.23.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-46618/ (Markdown: https://insights.sbomify.com/CVE-2026-46618/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46618
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46618
- OSV: https://osv.dev/vulnerability/CVE-2026-46618

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46618/
Summaries are generated and may contain mistakes; the official description above is the record.