Path Traversal in Checkmarx Github.com/checkmarx/ast-Cli
CVE-2026-77156
Incomplete validation of extracted archive entry paths in ast-cli's tar extraction logic on Linux and macOS (used when installing the Vorpal ASCA real-time engine and the SCA Resolver) would allow a malicious tar archive containing absolute or traversal path entries to write files outside the install directory. Windows builds were not affected, as the Windows extractor performs this path validation. Exploitation required substituting the archive served at "download.checkmarx.com". An attacker able to compromise that server and replace the archive could write arbitrary, executable files to arbitrary filesystem paths via this path traversal. Extraction now validates that each entry's destination path resolves within the working directory and rejects absolute paths.
Vulnerability class: Path Traversal (Directory Traversal)
Published .
CVSS v3 metric
CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- 596c5446-0ce5-4ba2-aa66-48b3b757a647 (product)
- 596c5446-0ce5-4ba2-aa66-48b3b757a647 (vendor-advisory)
Frequently asked questions
- What is CVE-2026-77156?
- CVE-2026-77156 is a medium-severity vulnerability in Checkmarx Github.com/checkmarx/ast-Cli, classified under Path Traversal. CVSS score: 6.4/10. Published 2026-10-22.
- How severe is CVE-2026-77156?
- Medium severity. CVSS v3 base score is 6.4 out of 10.