CVE-2026-40931 HIGH

CVE-2026-40931: Complete Bypass of CVE-2026-24884 Patch via Git-Delivered Symlink Poisoning in compressing

Vendor Node-Modules
Product compressing
Weakness CWE-59
Published April 21, 2026
Last update April 22, 2026

CVSS base score

8.4/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

Compressing is a compressing and uncompressing lib for node. Prior to 2.1.1 and 1.10.5, the patch for CVE-2026-24884 relies on a purely logical string validation within the isPathWithinParent utility. This check verifies if a resolved path string starts with the destination directory string but fails to account for the actual filesystem state. By exploiting this "Logical vs. Physical" divergence, an attacker can bypass the security check using a Directory Poisoning technique (pre-existing symbolic links). This vulnerability is fixed in 2.1.1 and 1.10.5.

Key dates

02Disclosure timeline

April 21, 2026 CVE published
April 22, 2026 Record updated