CVE-2026-39245
Summary
| CVE | CVE-2026-39245 |
|---|---|
| State | PUBLISHED |
| Assigner | mitre |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-09 22:17:04 UTC |
| Updated | 2026-07-09 22:17:04 UTC |
| Description | decompress before 4.2.2 contains an improper path containment check that enables directory traversal and arbitrary file write. The safeMakeDir function (index.js line 29) and the extraction path validation (index.js line 106) use String.indexOf() to verify the resolved path is within the output directory: realDestinationDir.indexOf(realOutputPath) !== 0. This check is flawed because it does not enforce a path separator boundary. For example, "/tmp/app_config".indexOf("/tmp/app") returns 0, incorrectly passing the check even though /tmp/app_config is outside /tmp/app. Combined with the unvalidated symlink creation in the same package, an attacker can write arbitrary files to directories adjacent to the extraction target. This is a bypass of the fix for CVE-2020-12265. The correct check requires appending a path separator: realParentPath.indexOf(realOutputPath + path.sep) !== 0. |
Risk And Classification
Problem Types: n/a
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/kevva/decompress/issues/115 | [email protected] | github.com | |
| nvd.nist.gov/vuln/detail/CVE-2020-12265 | [email protected] | nvd.nist.gov | |
| www.npmjs.com/package/decompress | [email protected] | www.npmjs.com | |
| github.com/kevva/decompress | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.