# CVE-2026-66065: ouroboros-ai: Incomplete fix of CVE-2026-47211: untrusted project .env can still reach RCE via omitted execution-routing keys

> Attackers can achieve remote code execution by shipping a malicious .env file in a cloned repository, bypassing approval gates in the Ouroboros AI agent runtime.

- **Severity:** High 8.4 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 3 Aug 2026
- **Updated:** 5 Aug 2026
- **Also known as:** GHSA-jv2h-4p9v-wf5w

## What is CVE-2026-66065?

CVE-2026-66065 is a high-severity code injection vulnerability in Q00 ouroboros, published on 3 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Ouroboros is a local-first runtime for AI coding agents that records their actions and applies user-defined policies to constrain behavior. Versions prior to 0.42.1 have an incomplete denylist. Several execution-routing keys of the same RCE class were omitted, so a malicious cloned repo can still reach arbitrary command execution by shipping a .env (auto-loaded at import, with no review step). The CVE-2026-47211 fix added _UNTRUSTED_ENV_DENYLIST to stop an untrusted project-directory .env from redirecting execution, but it did not account for all keys. The backend config-home and MCP/plugin roots bypass the approval gate by pointing the nested agent, MCP servers, and plugin roster at attacker config. Other variables re-enable blocked local transports, replace sub-agent prompts, switch backends, and lower tool approval classes, further weakening the approval gate. This issue has been fixed in version 0.42.1.

Weakness: CWE-94 (Improper Control of Generation of Code), CWE-15 (External Control of System or Configuration Setting)

## Which versions are affected by CVE-2026-66065?

2 open source packages ship an affected version, including ouroboros-ai.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ouroboros-ai` | PyPI | All versions | 0.42.1 |
| `ouroboros-ai` | PyPI | All versions | 0.42.1 |

## How do I fix CVE-2026-66065?

Upgrade ouroboros-ai to 0.42.1 or later.

## Is CVE-2026-66065 being exploited?

There is no known exploitation of CVE-2026-66065 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-66065 and fix it if it is affected.

What it is: CVE-2026-66065 is a high-severity code injection vulnerability in Q00 ouroboros, published on 3 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-66065 in the wild and no public exploit code.

Affected packages and fixed versions:
- ouroboros-ai (PyPI): affected all versions; fixed in 0.42.1
- ouroboros-ai (PyPI): affected all versions; fixed in 0.42.1

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-2026-66065/ (Markdown: https://insights.sbomify.com/CVE-2026-66065/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-66065
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-66065
- OSV: https://osv.dev/vulnerability/CVE-2026-66065

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-66065/
Summaries are generated and may contain mistakes; the official description above is the record.