# CVE-2026-50568: Fission: SanitizeFilePath lexical HasPrefix bypass permits sibling-directory escape

> Attackers can escape intended directories via lexical prefix bypass, enabling unauthorized file reads or writes in Fission serverless framework.

- **Severity:** Low 3.6 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Jun 2026
- **Updated:** 11 Jun 2026
- **Also known as:** GHSA-r5jh-q2mw-gcx4, GO-2026-6130

## What is CVE-2026-50568?

CVE-2026-50568 is a low-severity path traversal vulnerability in fission, published on 10 Jun 2026. It can only be exploited from the same machine or local 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 1.25.0, SanitizeFilePath in pkg/utils/utils.go validated that a path stayed under a safe directory by calling strings.HasPrefix(path, safedir). This is a lexical check, not a directory boundary check: /packages-extra/evil starts with /packages, so it passed. The function did not enforce a path-separator boundary, so any sibling directory whose name began with the safe-directory string was accepted. Callers included the builder's Clean handler (pkg/builder/builder.go:208) and the fetcher's Fetch / Upload handlers (pkg/fetcher/fetcher.go). A tenant who could pre-create or control a sibling directory under the fetcher / builder's shared volume could induce a write or read outside the intended safe directory. This issue has been patched in version 1.25.0.

Weakness: CWE-41 (Improper Resolution of Path Equivalence)

## Which versions are affected by CVE-2026-50568?

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 | 1.25.0 |
| `github.com/fission/fission` | Go | All versions | 1.25.0 |
| `github.com/fission/fission` | Go | All versions | 1.25.0 |

## How do I fix CVE-2026-50568?

Upgrade github.com/fission/fission to 1.25.0 or later.

## Is CVE-2026-50568 being exploited?

There is no known exploitation of CVE-2026-50568 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-50568 and fix it if it is affected.

What it is: CVE-2026-50568 is a low-severity path traversal vulnerability in fission, published on 10 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-50568 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/fission/fission (Go): affected all versions; fixed in 1.25.0
- github.com/fission/fission (Go): affected all versions; fixed in 1.25.0
- github.com/fission/fission (Go): affected all versions; fixed in 1.25.0

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-2026-50568/ (Markdown: https://insights.sbomify.com/CVE-2026-50568/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-50568
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-50568
- OSV: https://osv.dev/vulnerability/CVE-2026-50568

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-50568/
Summaries are generated and may contain mistakes; the official description above is the record.