CVE-2026-59874 node-tar: Negative tar entry size causes infinite loop in archive replace
An attacker can cause a denial of service in node-tar by providing a tar archive with a negative entry size, leading to an infinite loop during archive replacement.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-59874?
CVE-2026-59874 is a high-severity denial of service vulnerability in isaacs node-tar, published on 8 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
node-tar is a tar archive manipulation library for Node.js. Prior to 7.5.18, tar.replace accepts a checksum-valid tar header with a negative base-256 encoded entry size, causing the archive scanner to make no progress while repeatedly parsing the same header. This issue is fixed in version 7.5.18.
Weakness: CWE-835
Which versions are affected by CVE-2026-59874?
2 open source packages ship an affected version, including tar. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
tar npm | All versions | 7.5.18 |
tar npm | All versions | 7.5.18 |
Products include Isaacs Tar.
How do I fix CVE-2026-59874?
Upgrade tar to 7.5.18 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-59874 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-59874 exists.
Other vulnerabilities in isaacs node-tar
- CVE-2026-59873 node-tar: Decompression/parse DoS via unlimited input
- CVE-2026-23950 node-tar has Race Condition in Path Reservations via Unicode Ligature Collisions on macOS APFS
- CVE-2026-31802 node-tar Symlink Path Traversal via Drive-Relative Linkpath
- CVE-2026-29786 node-tar: Hardlink Path Traversal via Drive-Relative Linkpath
- CVE-2026-24842 node-tar Vulnerable to Arbitrary File Creation/Overwrite via Hardlink Path Traversal
Sources
Also known as CLEANSTART-2026-JQ76135, CLEANSTART-2026-NS47377, CLEANSTART-2026-RB55722, DEBIAN-CVE-2026-59874, ECHO-ddc0-f33b-a817, GHSA-8x88-c5mf-7j5w and 33 more.