node-tar: Uncontrolled recursion in mapHas/filesFilter allows uncatchable stack-overflow DoS via crafted long-path tar with member selection

Exploitation

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

CVSS

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

EPSS

• CVE-2026-73566: 0.53% estimated exploitation activity in the next 30 days; percentile 44.94 (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 node-tar (npm tar) contains an uncontrolled-recursion stack-exhaustion DoS in the internal mapHas helper used by filesFilter. When a consumer calls tar.t(...) or tar.x(...) with a non-empty member-selection list, node-tar installs a filter that closes over the recursive mapHas (src/list.ts:33-44). mapHas walks an entry path upward one path.dirname() call per recursion with no segment cap. A single crafted tar with a GNU-L (or PAX-x) long-path header can deliver a path of tens of thousands of /-separated segments (up to maxMetaEntrySize = 1 MiB). The recursion overflows the call stack, throwing an uncatchable RangeError that terminates the Node process on async/streaming consumers. Root Cause filesFilter (src/list.ts:27-51) is installed whenever a caller passes a member-selection list (src/list.ts:119-122, src/extract.ts:55-57). Its filter is invoked at src/parse.ts:253 (entry.ignore = entry.ignore || !this.filter(entry.path, entry)) inside Parser[CONSUMEHEADER] — and…

Published by the source

24 Jul 2026, 16:26 UTC

Last modified by the source

10 Sep 2026, 03:51 UTC

Source last checked

26 Oct 2026, 13:01 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-r292-9mhp-454m

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-r292-9mhp-454m

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# Patch Next advisory brief: CVE-2026-73566

Advisory: node-tar: Uncontrolled recursion in mapHas/filesFilter allows uncatchable stack-overflow DoS via crafted long-path tar with member selection
IDs: CVE-2026-73566, GHSA-r292-9mhp-454m
Record: https://patchnext.com/advisories/cve-2026-73566 (revision 2, source checked 26 Oct 2026, 13:01 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: tar 7.5.21. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm tar: affected <= 7.5.20; fixed in 7.5.21

## Suggested inspection (read-only)
- `npm ls tar --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 tar.
- 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://osv.dev/vulnerability/GHSA-r292-9mhp-454m (OSV record GHSA-r292-9mhp-454m lists affected ranges: npm tar >=0 <7.5.21 (fixed))
- Verified: https://github.com/advisories/GHSA-r292-9mhp-454m (GitHub-reviewed advisory GHSA-r292-9mhp-454m lists affected ranges: npm tar >=0 <=7.5.20)

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