PT-2026-67507 · Q00 · Ouroboros

CVE-2026-66065 · Published 2026-08-03 · Updated 2026-08-03

Mitre

CVSS v4.0

8.4

High

Base vector

AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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.

Fix

Code Injection

Weakness Enumeration

CWE-15

CWE-94

Related Identifiers

CVE-2026-66065

Affected Products

Ouroboros

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-66065 · Security Note
• https://github.com/Q00/ouroboros/releases/tag/v0.42.1 · Note
• https://github.com/Q00/ouroboros/security/advisories/GHSA-jv2h-4p9v-wf5w · Note