Summary
Fission: Zip Slip in pkg/utils/zip.go:Unarchive allows fetcher to write outside the destination directory
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.
Affected
- Project:
github.com/fission/fission - Versions: all up to and including v1.24.0
- Audited commit:
647c141 - Component:
pkg/utils/zip.go(Unarchive) - Configuration: default; triggered when the fetcher downloads and extracts a zip archive
Fix section (paste into the Fix / Patches field)
Fixed in v1.25.0 by:
- PR #3444 (commit
55704aca),Unarchivenow opens anos.Rooton the destination, validates each
archive entry name (rejects absolute paths and..traversal), and refuses symlink entries up front. Theos.Rootconfines everymkdir/createto the destination in the kernel.
Regression coverage: TestUnarchiveZipSlip in pkg/utils/zip_test.go exercises parent-traversal, absolute-path, and symlink entries.
Impact
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
CVE-2026-50567 has a CVSS score of 7.7 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.25.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-50567? CVE-2026-50567 is a high-severity path traversal vulnerability in github.com/fission/fission (go), affecting versions <= 1.24.0. It is fixed in 1.25.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- How severe is CVE-2026-50567? CVE-2026-50567 has a CVSS score of 7.7 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/fission/fission are affected by CVE-2026-50567? github.com/fission/fission (go) versions <= 1.24.0 is affected.
- Is there a fix for CVE-2026-50567? Yes. CVE-2026-50567 is fixed in 1.25.0. Upgrade to this version or later.
- Is CVE-2026-50567 exploitable, and should I be worried? Whether CVE-2026-50567 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-50567 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-50567? Upgrade
github.com/fission/fissionto 1.25.0 or later.