Path traversal in Checkmarx ast-cli tar extraction on Linux and macOS
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
Checkmarx ast-cli from 0 before 2.3.51 on Linux and macOS does not fully validate paths in tar archives it extracts (CWE-22). A malicious archive with absolute or traversal path entries can write files outside the install directory. Exploitation requires an attacker who can compromise download.checkmarx.com and replace the archive it serves, which allows writing arbitrary executable files to arbitrary paths. Windows builds are not affected.
Written with Claude Haiku 5.5 from the sources below · 2026-11-02
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade github.com/checkmarx/ast-cli to version 2.3.51, which checks that each extracted entry resolves within the working directory and rejects absolute paths.
Written with Claude Haiku 5.5 from the sources below · 2026-11-02
- Fix · CNA github.com/checkmarx/ast-cli (Checkmarx) Fixed in 2.3.51
Timeline
- 2026-10-22 Threatist record created from CVE-2026-77156
- 2026-10-23 Priority changed: MEDIUM → LOW
- 2026-11-02 CISA SSVC decision points changed
References
More Checkmarx vulnerabilities
- TI-2014-07204 Checkmarx CxSAST (formerly CxSuite) before 7.1.8 allows remote authenticated users to… CVSS 2.0HIGH 9.0
- TI-2026-79337 Checkmarx ast-cli auto-update skips checksum check before execution CVSS 4.0MEDIUM 6.3
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences