CVE-2026-53486: Decompress Archive Extraction Can Create Files Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-mp2f-45pm-3cg9",
  "modified" : "2026-07-06T20:27:38Z",
  "published" : "2026-07-06T20:27:38Z",
  "aliases" : [ "CVE-2026-53486" ],
  "summary" : "Decompress: Archive extraction can create files and links outside of the target directory",
  "details" : "### Impact\n\nWhen extracting an archive to a directory, a crafted archive can read or write files outside that directory. The flaw is in the code that writes the parsed entries, so it affects every format decompress handles: tar, tar.gz, tar.bz2, and zip by default, plus any others added through the plugins option.\n\nA link (hardlink) or symlink entry is created without checking where its target points. A hardlink can be aimed at any file the running process can read; that file then appears inside the output directory and its contents are exposed. A symlink can point outside the output directory and redirect a later write.\n\nThe path containment check used a string prefix comparison (`realPath.indexOf(outputPath) !== 0`). Output `/srv/out` does not contain `/srv/out-old`, but the prefix comparison treats it as inside, so an entry can escape into a sibling directory whose name starts with the output directory name.\n\nFile modes were applied as `mode & ~umask`, which does not remove the setuid, setgid, or sticky bits. A crafted entry can create a setuid or setgid file. This matters when extraction runs as root, for example in CI, containers, or install scripts.\n\nAny code that extracts archives from an untrusted or attacker-influenced source is affected. Archives are commonly downloaded before extraction, so this is reachable over the network in many setups.\n\n### Patches\n\nFixed in `@xhmikosr/decompress` 10.2.1 and 11.1.3. Link targets are now resolved and checked against the output directory, containment uses `path.relative`, and setuid, setgid, and sticky bits are removed.\n\nThe upstream `decompress` package is unmaintained, and all versions through its last release (4.2.1) have the same flaws. There is no upstream fix. Migrate to `@xhmikosr/decompress` 11.1.3 or later.\n\n### Workarounds\n\nExtract only archives you trust. Run extraction as a non-root user so the mode issue cannot create a privileged file. After extracting, reject any symlink or hardlink that points outside the target and any file with unexpected mode bits.\n\n### Resources\n\n* Related prior issue in the upstream project this package forks: CVE-2020-12265 / GHSA-qgfr-5hqp-vrw9\n* Fix commits and releases:\n  * https://github.com/XhmikosR/decompress/releases/tag/v10.2.1\n  * https://github.com/XhmikosR/decompress/releases/tag/v11.1.3\n  * https://github.com/XhmikosR/decompress/commit/aca5aac\n  * https://github.com/XhmikosR/decompress/commit/281cefa\n  * https://github.com/XhmikosR/decompress/commit/60b5299",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@xhmikosr/decompress"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "10.2.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@xhmikosr/decompress"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0"
      }, {
        "fixed" : "11.1.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "decompress"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "4.2.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/XhmikosR/decompress/security/advisories/GHSA-mp2f-45pm-3cg9"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/XhmikosR/decompress/commit/281cefa"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/XhmikosR/decompress/commit/60b5299"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/XhmikosR/decompress/commit/aca5aac"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/XhmikosR/decompress"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22", "CWE-59", "CWE-732" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-06T20:27:38Z",
    "nvd_published_at" : null
  }
}