Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
AV AC PR UI S C I A CVSS EPSS %ile KEV L L N N U N H N 6.2 .0034 27.1 —
AFFECTED Product Versions Fixed n/a n/a – —
TIMELINE Apr 6 Reserved by mitre Jul 9 EXPLOIT PUBLISHED — CVE-2026-39245. Public exploit reference added. Jul 9 Published (CNA: mitre)
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.
| Date | Event | Detail |
|---|---|---|
| April 6, 2026 | Reserved | Reserved by mitre |
| July 9, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-39245. Public exploit reference added. |
| July 9, 2026 | Published | Published (CNA: mitre) |
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|---|---|---|---|
| n/a | n/a | — | n/a | — |
Authoritative record: CVE-2026-39245 at cve.org
Weaknesses: CWE-22
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-39245 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.