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Vulnerability · Published Jun 10, 2026 · Assigned by GitHub_M

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

Low 3.6

In plain English

A low-severity security flaw in fission from fission. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)3.6Low
Exploit odds (30 days)0.1%top 98.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Gogithub.com/fission/fission1.25.0GHSA-r5jh-q2mw-gcx4
Gogithub.com/fission/fission1.25.0GO-2026-6130

Affected products (as reported)

VendorProductVersions
fission fission < 1.25.0

Weakness: CWE-41 · Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N

References