What’s Vulnerable › Vulnerabilities

CVE-2026-50567: Fission: Zip Slip in pkg/utils/zip.go:Unarchive allows fetcher to write outside the destination directory

• Severity: high (CVSS 7.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-10 · updated 2026-06-17
• Weakness: CWE-22

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, Unarchive in pkg/utils/zip.go joined each archive entry name with the destination directory via filepath.Join and wrote the result without checking whether the resolved path stayed under the destination. A zip entry named ../../tmp/evil therefore landed at /tmp/evil. An attacker who could control a Package.Spec.Source.URL or Deployment.URL archive could induce the fetcher (running as the per-environment pod's fission-fetcher sidecar) to write files anywhere that process could reach: into other tenants' /packages/<ns>/ directories, into mounted secret/config volumes, or into the fetcher's own binary. This issue has been patched in version 1.25.0.

Affected products

• fission: before 1.25.0

References

• https://github.com/fission/fission/pull/3444
• https://github.com/fission/fission/releases/tag/v1.25.0
• https://github.com/fission/fission/security/advisories/GHSA-q6vm-xqc9-v3ff

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