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Fission: SanitizeFilePath lexical HasPrefix bypass permits sibling-directory escape

Type: advisorySources: OSV

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.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-50568
Confirmed fixed CVEs
Not specified
Updated in this feed
3 Nov 2026, 04:30 UTC · Revision 1

Source evidence

Fission: SanitizeFilePath lexical HasPrefix bypass permits sibling-directory escape

core-osv · Original source

Published 10 Jun 2026, 17:31 UTC

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.

osv:CVE-2026-50568
Complete source record
{
  "id": "376bd01ac6cb4dc844a6c64564995c9225815966d11331e96c44d9eea3d4fdb2",
  "url": "https://osv.dev/vulnerability/CVE-2026-50568",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Fission: SanitizeFilePath lexical HasPrefix bypass permits sibling-directory escape",
    "summary": "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.",
    "evidence": "osv:CVE-2026-50568",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CVE-2026-50568",
      "aliases": [
        "CVE-2026-50568",
        "GHSA-r5jh-q2mw-gcx4",
        "GO-2026-6130"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/fission/fission",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "ae970aaa9bc76ec93d748bdaf03fd7523b6b6a62"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.25.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "ae970aaa9bc76ec93d748bdaf03fd7523b6b6a62"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.25.0"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.25.0"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.24.0",
            "v1.23.0-rc1",
            "v1.23.0",
            "v1.22.0",
            "v1.22.0-rc2",
            "v1.22.0-rc1",
            "v1.21.0",
            "v1.21.0-rc2",
            "v1.21.0-rc1",
            "v1.20.5",
            "v1.20.4",
            "v1.20.3",
            "v1.20.2",
            "v1.20.1",
            "v1.20.0",
            "v1.20.0-rc2",
            "v1.20.0-rc1",
            "v1.19.0",
            "v1.19.0-rc2",
            "v1.19.0-rc1",
            "v1.18.0",
            "v1.18.0-rc2",
            "v1.18.0-rc1",
            "v1.17.0",
            "v1.17.0-rc2",
            "v1.16.0",
            "v1.17.0-rc1",
            "v1.16.0-rc2",
            "v1.16.0-rc1",
            "v1.15.1",
            "v1.15.0",
            "v1.15.0-rc2",
            "v1.15.0-rc1",
            "v1.14.1",
            "1.14.1",
            "v1.14.0",
            "1.14.0",
            "v1.13.1",
            "1.13.1",
            "v1.13.0",
            "1.13.0",
            "v1.8.0",
            "1.8.0",
            "v1.7.1",
            "1.7.1",
            "v1.7.0",
            "1.7.0",
            "v1.7.0-rc.2",
            "1.7.0-rc.2",
            "v1.7.0-rc.1",
            "1.7.0-rc.1",
            "v1.6.0",
            "1.6.0",
            "1.3.0",
            "1.0-rc1",
            "0.10.0",
            "0.7.2",
            "0.6.1",
            "latest",
            "0.6.0",
            "0.4.1",
            "0.4.0",
            "0.4.0rc",
            "0.3.0",
            "0.3.0-rc",
            "v0.2.1",
            "v0.2.0-20170901",
            "nightly20170705",
            "nightly20170621",
            "alpha20170124",
            "kubecon"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-50568.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:25.894266734Z",
      "provider": "osv",
      "references": [
        "https://github.com/fission/fission/releases/tag/v1.25.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50568.json",
        "https://github.com/fission/fission/security/advisories/GHSA-r5jh-q2mw-gcx4",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50568",
        "https://github.com/fission/fission/pull/3445",
        "https://github.com/fission/fission/pull/3446"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-41"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50568.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-50568",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 492451,
  "published_at": "2026-06-10T17:31:49.917+00:00"
}