TI-2026-29585 Aliases CVE-2026-40931 GHSA-4c3q-x735-j3r5

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

HIGH 72CWE-59Published 2026-04-21 · Updated 2026-04-22

Key facts

Attack vector: Local
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · High · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00258 17th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed compressing (node-modules): 2.1.1, 1.10.5compressing (npm): 2.1.1, 1.10.5

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
node-modules	compressing	2.0.0 to before 2.1.1; before 1.10.5	2.1.1, 1.10.5	Patch available	CNA
—	compressing (npm)	2.0.0 to before 2.1.1	2.1.1	Patch available	GHSA-4c3q-x735-j3r5
—	compressing (npm)	before 1.10.5	1.10.5	Patch available	GHSA-4c3q-x735-j3r5

compressing Vendornode-modules Affected 2.0.0 to before 2.1.1; before 1.10.5 Fixed in 2.1.1, 1.10.5 Patch available CNA
compressing (npm) Vendor— Affected 2.0.0 to before 2.1.1 Fixed in 2.1.1 Patch available GHSA-4c3q-x735-j3r5
compressing (npm) Vendor— Affected before 1.10.5 Fixed in 1.10.5 Patch available GHSA-4c3q-x735-j3r5

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:node-modules:compressing::::::node.js::*	before 1.10.5; 2.0.0 to before 2.1.1	Vulnerable	node-modules

cpe:2.3:a:node-modules:compressing:*:*:*:*:*:node.js:*:* Versions before 1.10.5; 2.0.0 to before 2.1.1 Vulnerable ·node-modules

Remediation

Fix · CNA compressing (node-modules) Fixed in 2.1.1, 1.10.5
Fix · GHSA-4c3q-x735-j3r5 compressing (npm) Fixed in 2.1.1 Advisory →
Fix · GHSA-4c3q-x735-j3r5 compressing (npm) Fixed in 1.10.5 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-40931
2026-10-03 Alias added: GHSA-4c3q-x735-j3r5

References

TI-2026-20070 Compressing Vulnerable to Arbitrary File Write via Symlink Extraction CVSS 3.1HIGH 8.4

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences