CVE-2026-66065
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.
Scoring
- Severity
- HIGH
- CVSS base score
- 8.4
- CVSS vector
- 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
- EPSS probability
- 0.30%
- CWE
- CWE-15, CWE-94
- Published
- 2026-08-03
- Last modified
- 2026-08-05
Affected products
- Q00 ouroboros
Weakness type
Related vulnerabilities
- CVE-2026-19592 — OpenAI Codex CLI for Windows, macOS, and Linux and Codex Desktop for Windows and macOS...
- CVE-2026-19593 — OpenAI Codex Desktop for Windows and macOS automatically inspected Git metadata and working-tree...
- CVE-2026-16708 — IBM Db2 Mirror for i is affected by multiple vulnerabilities
- CVE-2026-19884 — In Eclipse Theia versions up to and including 1.69.0, opening a folder starts source control...
- CVE-2026-73661 — FreePBX: Authenticated Framework AUTHTYPE Can Be Restored From a Crafted Backup
- CVE-2026-56567 — HCL iControl is affected by multiple security vulnerabilities.
- CVE-2026-46485 — Dash: Users can write to config despire permissions (OIDC tested)
- CVE-2026-44768 — Security misconfiguration in SAP CRM (WebClient UI)