CVE-2026-5704

A flaw was found in tar. A remote attacker could exploit this vulnerability by crafting a malicious archive, leading to hidden file injection with fully attacker-controlled content. This bypasses pre-extraction inspection mechanisms, potentially allowing an attacker to introduce malicious files onto a system without detection.

What this means for your business

It affects Gnu 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, with an ordinary user 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 34% of all known flaws.

What to do

1Check whether your company or your suppliers run Gnu Tar, and which version. The affected versions are listed further down this page.
2If you do, follow the vendor's guidance. No patch reference has been published yet.

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.

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Scoring

CVSS: 5.0 (v3.1)
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
Weakness: CWE-434
Assigned by: secalert@redhat.com

Dates

Published: 2026-04-06
Last modified: 2026-09-22
Sources: NVD

Affected products

Gnu Tarall versions
Redhat Hardened Imagesall versions
Redhat Enterprise Linux6.0, 7.0, 8.0, 9.0, 10.0

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