CVE-2026-50567CWE-22

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

High · published June 10, 2026

CVSS v3.1
7.7
EPSS
0%
Percentile
38.0
In the wild
Unconfirmed
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 1.25.0, 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.

The record
Technical detail
CVSS v3.1
7.7 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00447 · 38.0th percentile
Weakness
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Published
2026-06-10T17:30Z
EPSS history
Timeline
  • 10 JUN 17:30Z
    Fission: Zip Slip in pkg/utils/zip.go:Unarchive allows fetcher to write outside the destination directory
    cvelistv5