CVE-2026-77156
ast-cli: Path traversal in tar extraction on Linux/macOS allows writes outside the install directory
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
ast-cli: Path traversal in tar extraction on Linux/macOS allows writes outside the install directory
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.
- Record
CVE-2026-77156- CVSS 4.0
- 6.3 Medium
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 - CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
EUVDEUVD-2026-108269
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.
- Record
EUVD-2026-108269- CVSS 4.0
- 6.3 Medium
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 - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-77156- CVSS 4.0
- 6.3 Medium
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
OSV
ast-cli: Path traversal in tar extraction on Linux/macOS allows writes outside the install directory
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.
- Record
CVE-2026-77156- CVSS 4.0
- 6.3 Medium
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 - Weakness
- CWE-22
- Updated
- 2026-11-04
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | OSV | |
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-77156 is a medium vulnerability (CVSS 6.3) in Checkmarx Github.com/checkmarx/ast-cli, published October 22, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.35%, the 28th percentile. No source names a fixed version.