CVE-2026-77156CWE-22path-traversal

CVE-2026-77156

Medium · published October 22, 2026

CVSS v3.1
6.4
EPSS
0%
Percentile
27.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.4 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H
CVSS v4.0
6.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H
EPSS
0.00349 · 27.3th percentile
Weakness
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Published
2026-10-22T22:17Z
References (2)
EPSS history
Timeline
  • 24 OCT 04:02Z
    EPSS moved — → 0%
    epss
  • 22 OCT 17:44Z
    ast-cli: Path traversal in tar extraction on Linux/macOS allows writes outside the install directory
    cvelistv5
  • 22 OCT 17:44Z
    ast-cli: Path traversal in tar extraction on Linux/macOS allows writes outside the install directory
    cvelistv5