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


- **Severity:** Medium 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`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 22 Oct 2026
- **Updated:** 22 Oct 2026
- **Also known as:** GHSA-vf6p-x2fw-5hcg

## What is CVE-2026-77157?

CVE-2026-77157 is a medium-severity vulnerability in github.com/checkmarx/ast-cli, published on 22 Oct 2026. 

### Official 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.

Weakness: CWE-353 (Missing Support for Integrity Check)

## Which versions are affected by CVE-2026-77157?


## How do I fix CVE-2026-77157?

No fix has been published for CVE-2026-77157 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-77157 being exploited?

There is no known exploitation of CVE-2026-77157 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-77157 and fix it if it is affected.

What it is: CVE-2026-77157 is a medium-severity vulnerability in github.com/checkmarx/ast-cli, published on 22 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-77157 in the wild and no public exploit code.

Affected product: github.com/checkmarx/ast-cli. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-77157/ (Markdown: https://insights.sbomify.com/CVE-2026-77157/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-77157
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-77157
- OSV: https://osv.dev/vulnerability/CVE-2026-77157

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-77157/
Summaries are generated and may contain mistakes; the official description above is the record.