{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "apko allows users to build and publish OCI container images built from apk packages. From version 0.14.8 to before version 1.2.5, a crafted .apk could install a TypeSymlink tar entry whose target pointed outside the build root, and a subsequent directory-creation or file-write entry in the same or later archive could traverse that symlink to reach host paths the build user could write to. This issue has been patched in version 1.2.5."
    }
  ],
  "id": "CVE-2026-42574",
  "lastModified": "2026-05-09T20:16:29.420",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-05-09T20:16:29.420",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/chainguard-dev/apko/commit/f5a96e1299ac81c7ea9441705ec467688086f442"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/chainguard-dev/apko/pull/2187"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/chainguard-dev/apko/releases/tag/v1.2.5"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/chainguard-dev/apko/security/advisories/GHSA-qq3r-w4hj-gjp6"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-22"
        },
        {
          "lang": "en",
          "value": "CWE-59"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "chainguard.dev/apko"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.14.8"
            },
            {
              "fixed": "1.2.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-42574"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22",
      "CWE-59"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-04T21:26:47Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\n\nA crafted `.apk` could install a `TypeSymlink` tar entry whose target pointed outside the build root, and a subsequent directory-creation or file-write entry in the same or later archive could traverse that symlink to reach host paths the build user could write to. The root cause was the `sanitizePath` helper in `pkg/apk/fs/rwosfs.go`, which rejected only lexical `..` traversal and did not resolve or refuse symlinks. Every disk-backed `DirFS` method that handed its caller-supplied path to a symlink-following stdlib call \u2014 `ReadFile`, `WriteFile`, `Chmod`, `Chown`, `Chtimes`, `MkdirAll`, `Mkdir`, and `Mknod` \u2014 was affected. The reachable primitive from a malicious APK during tar extraction is the `MkdirAll` / `Mkdir` / `WriteFile` chain via `apko build-cpio` and disk-backed consumers such as `melange`; the remaining sinks are reachable by direct callers of the `pkg/apk/fs` package. The in-memory `tarfs` install path used by `apko build`, `apko publish`, and `apko build-minirootfs` is not affected.\n\n### Patches\n\nFixed in apko **v1.2.5** by [#2187](https://github.com/chainguard-dev/apko/pull/2187) / commit [f5a96e1](https://github.com/chainguard-dev/apko/commit/f5a96e1299ac81c7ea9441705ec467688086f442), which scopes all `DirFS` operations through a Go 1.24 `*os.Root`. The `sanitizePath` helper has been removed; `*os.Root` refuses traversal via `..`, absolute-target symlinks, relative-target symlinks, and hardlinks by construction. Regression tests in `pkg/apk/apk/path_traversal_test.go` cover each composite primitive.\n\n### Workarounds\n\nNo complete workaround. Operators running pre-1.2.5 apko (or downstream tools such as melange that embed pre-1.2.5 `pkg/apk/fs`) should upgrade. Consuming only APKs from trusted, signed sources reduces but does not eliminate exposure.\n\n### Resources\n\n- https://github.com/chainguard-dev/apko/pull/2187\n- https://github.com/chainguard-dev/apko/commit/f5a96e1299ac81c7ea9441705ec467688086f442\n- https://github.com/chainguard-dev/apko/releases/tag/v1.2.5\n- Related: GHSA-5g94-c2wx-8pxw (CVE-2026-25121) \u2014 prior lexical `..` traversal fix\n\n### Credits\n\napko thanks Oleh Konko ([@1seal](https://github.com/1seal) from [1seal.org](https://1seal.org/)) for the initial report of the symlink-escape class, and to [@Xh081iX](https://github.com/Xh081iX) for a follow-up set of reports covering additional reachable primitives (`ReadFile`, `Chmod`/`Chown`, `Mknod`, `MkdirAll`/`Mkdir`) that shaped the comprehensive fix.",
  "id": "GHSA-qq3r-w4hj-gjp6",
  "modified": "2026-05-04T21:26:47Z",
  "published": "2026-05-04T21:26:47Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/chainguard-dev/apko/security/advisories/GHSA-qq3r-w4hj-gjp6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/chainguard-dev/apko/pull/2187"
    },
    {
      "type": "WEB",
      "url": "https://github.com/chainguard-dev/apko/commit/f5a96e1299ac81c7ea9441705ec467688086f442"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/chainguard-dev/apko"
    },
    {
      "type": "WEB",
      "url": "https://github.com/chainguard-dev/apko/releases/tag/v1.2.5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "apko dirFS has a symlink-following path traversal that allows multiple entry points to escape the build root"
}