High severity8.4NVD Advisory· Published Apr 21, 2026· Updated Apr 23, 2026
CVE-2026-40931
CVE-2026-40931
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
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
compressingnpm | >= 2.0.0, < 2.1.1 | 2.1.1 |
compressingnpm | < 1.10.5 | 1.10.5 |
Affected products
1Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
3- github.com/node-modules/compressing/security/advisories/GHSA-4c3q-x735-j3r5nvdExploitMitigationVendor AdvisoryWEB
- github.com/advisories/GHSA-4c3q-x735-j3r5ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-40931ghsaADVISORY
News mentions
6- The Good, the Bad and the Ugly in Cybersecurity – Week 20SentinelOne Labs · May 15, 2026
- How Rapid7 is bringing Cyber GRC closer to security operationsRapid7 Blog · May 12, 2026
- LMDeploy CVE-2026-33626 Flaw Exploited Within 13 Hours of DisclosureThe Hacker News · Apr 24, 2026
- Hypersonic Supply Chain Attacks: One Solution That Didn’t Need to Know the PayloadSentinelOne Labs · Apr 22, 2026
- Shared Dictionaries: compression that keeps up with the agentic webCloudflare Blog · Apr 17, 2026
- Unweight: how we compressed an LLM 22% without sacrificing qualityCloudflare Blog · Apr 17, 2026