CVE-2026-40931 json
Complete Bypass of CVE-2026-24884 Patch via Git-Delivered Symlink Poisoning in compressing
published 6mo ago modified 14d ago also EUVD-2026-24488 , GHSA-4c3q-x735-j3r5
- cvss
- 8.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 17%
- public exploits
- 0
- none known
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.
Patch / fix
- npm compressing 1.10.5, 2.1.1
- node-modules compressing 1.10.5, 2.1.1
Is CVE-2026-40931 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- total
- Assessed
- 6mo ago
Exploit prediction
0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- github.com https://github.com/node-modules/compressing/security/advisories/GHSA-4c3q-x735-j3r5 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.1 | 8.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | compressing | >=2.0.0, <2.1.1 <1.10.5 |
2.1.1 1.10.5 |
Affected products
- node-modules compressing
Classification
- Weakness
-
- CWE-59 Improper Link Resolution Before File Access
References
-
github.com
/node-modules/compressing/security/advisories/GHSA-4c3q-x735-j3r5
exploit, web, mitigation, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-40931
advisory
-
github.com
/node-modules/compressing
package
Sources
- CVE List CVE-2026-40931
- GitHub Advisory GHSA-4c3q-x735-j3r5
- NVD CVE-2026-40931
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.