adm-zip extraction preserves SUID/SGID bits from untrusted ZIPs -> local privilege escalation

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-102282: 0.20% estimated exploitation activity in the next 30 days; percentile 9.85 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary adm-zip applies the Unix permission bits stored in a zip entry directly to the extracted file via fs.chmodSync() when keepOriginalPermission=true is passed to extractAllTo()/extractEntryTo() — and it never filters the setuid/setgid/sticky bits out of those bits. A zip crafted by an attacker can therefore produce an extracted binary with mode 04755. When extraction runs as root (the default posture in Docker builds, CI runners, and privileged install steps — the exact environments where this flag is used), the resulting root-owned setuid file is executed later by a lesser-privileged user, turning the attacker's code into a root execution. Details The mode a zip entry wants is read back from the external file attributes in the header, and the mask used keeps every special bit: 0xfff is 0o7777 — it preserves setuid (0o4000), setgid (0o2000) and the sticky bit (0o1000) along with the rwx bits. Shifting by 16 is the standard Unix convention for where zip stores the mode; the mask…

Published by the source

29 Sep 2026, 18:24 UTC

Last modified by the source

8 Oct 2026, 10:56 UTC

Source last checked

26 Oct 2026, 13:02 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-j5f4-cc29-5x44

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-j5f4-cc29-5x44

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-j5f4-cc29-5x44

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# Patch Next advisory brief: CVE-2026-102282

Advisory: adm-zip extraction preserves SUID/SGID bits from untrusted ZIPs -> local privilege escalation
IDs: CVE-2026-102282, GHSA-j5f4-cc29-5x44
Record: https://patchnext.com/advisories/cve-2026-102282 (revision 3, source checked 26 Oct 2026, 13:02 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: adm-zip 0.6.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm adm-zip: affected <= 0.6.0; fixed in 0.6.1

## Suggested inspection (read-only)
- `npm ls adm-zip --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on adm-zip.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-j5f4-cc29-5x44 (GitHub-reviewed advisory GHSA-j5f4-cc29-5x44 lists affected ranges: npm adm-zip >=0 <=0.6.0)
- Verified: https://osv.dev/vulnerability/GHSA-j5f4-cc29-5x44 (OSV record GHSA-j5f4-cc29-5x44 lists affected ranges: npm adm-zip >=0 <0.6.1 (fixed))

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