Vulnerability · Published Apr 21, 2026 · Assigned by GitHub_M
CVE-2026-40931Complete Bypass of CVE-2026-24884 Patch via Git-Delivered Symlink Poisoning in compressing
High 8.4
In plain English
A high-severity security flaw in compressing from node-modules. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 18% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | compressing | 2.1.1 | GHSA-4c3q-x735-j3r5 |
| npm | compressing | 1.10.5 | GHSA-4c3q-x735-j3r5 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| node-modules | compressing | >=2.0.0, < 2.1.1< 1.10.5 |
Weakness: CWE-59 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H