decompress: Archive extraction can create files and links outside the target directory

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No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

The decompress package for Node.js extracts archives. Prior to 10.2.1 and 11.1.3, archive extraction can create files and links outside the target directory. When extracting an archive to a directory, a crafted archive can read or write files outside that directory because hardlink and symlink entries are created without checking where targets point, path containment used a string prefix comparison, and file modes failed to remove setuid, setgid, or sticky bits. This issue is fixed in @xhmikosr/decompress versions 10.2.1 and 11.1.3.

Source published

14 Jul 2026 20:07:14 UTC

Source modified

15 Jul 2026 13:26:56 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

The decompress package for Node.js extracts archives. Prior to 10.2.1 and 11.1.3, archive extraction can create files and links outside the target directory. When extracting an archive to a directory, a crafted archive can read or write files outside that directory because hardlink and symlink entries are created without checking where targets point, path containment used a string prefix comparison, and file modes failed to remove setuid, setgid, or sticky bits. This issue is fixed in @xhmikosr/decompress versions 10.2.1 and 11.1.3.

Source published

14 Jul 2026 21:17:05 UTC

Source modified

24 Oct 2026 21:10:00 UTC

Observed here

25 Oct 2026 13:17:16 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

### Impact When 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. A 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. The 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. File 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. Any 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. ### Patches Fixed 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. The 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. ### Workarounds Extract 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. ### Resources * Related prior issue in the upstream project this package forks: CVE-2020-12265 / GHSA-qgfr-5hqp-vrw9 * Fix commits and releases: * https://github.com/XhmikosR/decompress/releases/tag/v10.2.1 * https://github.com/XhmikosR/decompress/releases/tag/v11.1.3 * https://github.com/XhmikosR/decompress/commit/aca5aac * https://github.com/XhmikosR/decompress/commit/281cefa * https://github.com/XhmikosR/decompress/commit/60b5299

Source published

6 Jul 2026 20:27:38 UTC

Source modified

10 Sep 2026 03:50:12 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Publisher rating · CRITICAL