# CVE-2026-66902: Google::Auth versions before 0.06 for Perl run a command named in an external_account credentials JSON via an ungated system call.


- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 4 Aug 2026
- **Updated:** 5 Aug 2026
- **Also known as:** GHSA-vjmh-7f4c-cx88

## What is CVE-2026-66902?

CVE-2026-66902 is a critical vulnerability in CJCOLLIER Google::Auth, published on 4 Aug 2026. 

### Official description

Google::Auth versions before 0.06 for Perl run a command named in an external_account credentials JSON via an ungated system call.

The Pluggable subclass reads credential_source.executable.command from the credentials JSON and runs it as `system($command)`, a single argument call that passes the whole string to /bin/sh -c. The executable's environment_variables map from the same JSON is copied into %ENV first. No opt-in gate guards the call. make_creds selects the Pluggable subclass whenever credential_source.executable is present, so the path is reached from the standard Application Default Credentials flow, including a "type": "external_account" configuration read from the file named by GOOGLE_APPLICATION_CREDENTIALS. Configurations without credential_source.executable do not select this subclass and do not reach the call.

Any caller that builds credentials from a configuration it does not fully control runs the embedded command with the privileges of the application process.

Weakness: CWE-829 (Inclusion of Functionality from Untrusted Control Sphere), CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-66902?


## How do I fix CVE-2026-66902?

No fix has been published for CVE-2026-66902 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-66902 being exploited?

There is no known exploitation of CVE-2026-66902 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-66902 and fix it if it is affected.

What it is: CVE-2026-66902 is a critical vulnerability in CJCOLLIER Google::Auth, published on 4 Aug 2026. 
Exploitation: There is no known exploitation of CVE-2026-66902 in the wild and no public exploit code.

Affected product: CJCOLLIER Google::Auth. 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-2026-66902/ (Markdown: https://insights.sbomify.com/CVE-2026-66902/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-66902
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-66902
- OSV: https://osv.dev/vulnerability/CVE-2026-66902

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-66902/
Summaries are generated and may contain mistakes; the official description above is the record.