CVE-2026-59874: tar — Exploit & Fix

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.

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CVSS v3.1 Score

7.5

HIGH

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

EPSS — Exploit Prediction

0.0042

Probability of exploitation

0.34%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-835 CWE-835

Affected Products

Vendor	Product	Versions
isaacs	tar	< 7.5.18

References

Advisories & Patches

https://github.com/isaacs/node-tar/commit/9e78bf058b2c22dd4d52e00d8922d5c06fc2f7b5 https://github.com/isaacs/node-tar/security/advisories/GHSA-8x88-c5mf-7j5w https://github.com/isaacs/node-tar/security/advisories/GHSA-8x88-c5mf-7j5w

Exploits

https://github.com/isaacs/node-tar/security/advisories/GHSA-8x88-c5mf-7j5w https://github.com/isaacs/node-tar/security/advisories/GHSA-8x88-c5mf-7j5w

Other References

https://github.com/isaacs/node-tar/releases/tag/v7.5.18

Frequently Asked Questions

What is CVE-2026-59874? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-59874? +

CVE-2026-59874 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0042, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-59874? +

CVE-2026-59874 affects products from isaacs, specifically: tar. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-59874? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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