# CVE-2026-49821: Fission: Cross-namespace Environment reference in Package allows build-time command execution and SA token exfiltration

> Attackers can execute commands and steal service account tokens by referencing environments across namespaces in Fission packages.

- **Severity:** High 7.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Jun 2026
- **Updated:** 10 Jun 2026
- **Also known as:** GHSA-vjhc-cf4p-72q4, GO-2026-5859

## What is CVE-2026-49821?

CVE-2026-49821 is a high-severity missing authorization vulnerability in fission, published on 10 Jun 2026. Any signed-in user can exploit it over the network, 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 1.24.0, Fission's buildermgr controller processed Package CRDs without verifying that Package.spec.environment.namespace matched Package.metadata.namespace. This issue has been patched in version 1.24.0.

Weakness: CWE-862 (Missing Authorization), CWE-441 (Unintended Proxy or Intermediary)

## Which versions are affected by CVE-2026-49821?

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 | 1.24.0 |
| `github.com/fission/fission` | Go | All versions | 1.24.0 |
| `github.com/fission/fission` | Go | All versions | 1.24.0 |

## How do I fix CVE-2026-49821?

Upgrade github.com/fission/fission to 1.24.0 or later.

## Is CVE-2026-49821 being exploited?

There is no known exploitation of CVE-2026-49821 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-49821 and fix it if it is affected.

What it is: CVE-2026-49821 is a high-severity missing authorization vulnerability in fission, published on 10 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-49821 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/fission/fission (Go): affected all versions; fixed in 1.24.0
- github.com/fission/fission (Go): affected all versions; fixed in 1.24.0
- github.com/fission/fission (Go): affected all versions; fixed in 1.24.0

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-2026-49821/ (Markdown: https://insights.sbomify.com/CVE-2026-49821/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-49821
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-49821
- OSV: https://osv.dev/vulnerability/CVE-2026-49821

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-49821/
Summaries are generated and may contain mistakes; the official description above is the record.