# CVE-2026-77157: ast-cli: Auto-update downloads are not verified against a checksum before execution

Status: published. Published: 2026-10-22. Updated: 2026-11-02.

ast-cli downloads two helper binaries, the Vorpal ASCA real-time engine and the SCA Resolver, from "download.checkmarx.com" as part of its auto-update flow, triggered by the Checkmarx’s "VSCode/JetBrains" extensions and by cx scan "sca-realtime".



Prior to the fix, the downloaded archive was not verified against a checksum before extraction and execution. An attacker able to substitute the served archive could deliver an arbitrary binary that ast-cli would extract and execute the contents of the archive, since no integrity check was performed on the download.



Successful exploitation requires compromising "download.checkmarx.com" and replacing the served archive with one containing an attacker-controlled binary. If the served archive had been replaced that way, any developer machine or CI pipeline invoking ASCA (via Checkmarx's VSCode/JetBrains extensions) or cx scan "sca-realtime" on an affected version would have extracted and executed that binary in place of the intended download.



The download is now verified against a published SHA-256 checksum before extraction.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Checkmarx / github.com/checkmarx/ast-cli (github.com/checkmarx/ast-cli): ≥ 0; ≤ 2.3.59 (affected, semver); 2.3.60 (unaffected, semver). Source: CNA: Checkmarx

## Severity and prioritization

- 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; source: CNA: Checkmarx

- 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; source: CNA: Checkmarx

- CISA KEV: No listing in collected sources

- EPSS: 0.14% as of 2026-11-01; percentile 3.58%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-353

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/Checkmarx/ast-cli (CNA: Checkmarx; product)

- https://github.com/Checkmarx/ast-cli/security/advisories/GHSA-vf6p-x2fw-5hcg (CNA: Checkmarx; third-party-advisory)

## Provenance

- CNA: Checkmarx: https://www.cve.org/CVERecord?id=CVE-2026-77157; retrieved 2026-11-02; source updated 2026-11-02

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-77157; retrieved 2026-11-02; source updated Not reported

Revision: 92cc9b48607d1c46cf4022925b8224d9e9a865a60fa723f40f5b2523f1097dd6

Canonical: https://y2.dev/cve/CVE-2026-77157