CVE-2026-40931 PUBLISHED

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

Assigner: GitHub_M
Reserved: 15.04.2026 Published: 21.04.2026 Updated: 21.04.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 8.4

Product Status

Vendor node-modules
Product compressing
Versions
  • Version >=2.0.0, < 2.1.1 is affected
  • Version < 1.10.5 is affected

References

Problem Types

  • CWE-59: Improper Link Resolution Before File Access ('Link Following') CWE