CVE-2026-29786

node-tar is a full-featured Tar for Node.js. Prior to version 7.5.10, tar can be tricked into creating a hardlink that points outside the extraction directory by using a drive-relative link target such as C:../target.txt, which enables file overwrite outside cwd during normal tar.x() extraction. This issue has been patched in version 7.5.10.

What this means for your business

It affects Isaacs Tar. It matters if your company, or a supplier that handles your data, runs it.
Code showing how to exploit it has been published, but real attacks have not been confirmed.
An attacker can use it only with access to the machine itself, without a login, but only after tricking someone into an action such as opening a file or a link.
FIRST's prediction model gives it a 0.4% chance of attack attempts being seen in the next 30 days, ranking above 37% of all known flaws.

What to do

1Check whether your company or your suppliers run Isaacs Tar, and which version. The affected versions are listed further down this page.
2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Check if you’re exposed Book a call

Scoring

CVSS: 6.3 (v3.1)
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N
CVSS v4: 8.2
Weakness: CWE-22
Assigned by: security-advisories@github.com

Dates

Published: 2026-03-07
Last modified: 2026-09-01
Sources: NVD

Affected products

Isaacs Tar- 7.5.10

As listed in the NVD configuration data. Not a statement about your estate.