{"cve":"CVE-2026-66065","nvd":{"published":"2026-08-03T21:16:41.193","modified":"2026-10-23T21:10:00.157","status":"Deferred","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.","cvss_v4":{"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","score":8.4},"cvss_v3":null,"cwes":["CWE-15","CWE-94"],"references":["https://github.com/Q00/ouroboros/releases/tag/v0.42.1","https://github.com/Q00/ouroboros/security/advisories/GHSA-jv2h-4p9v-wf5w"],"products":[],"source":"nvd","synced_at":"2026-10-24T16:53:34.184483516+00:00"},"epss":{"cve":"CVE-2026-66065","score":0.0024,"percentile":0.14999,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-jv2h-4p9v-wf5w","url":"https://osv.dev/vulnerability/GHSA-jv2h-4p9v-wf5w","summary":"ouroboros-ai: Incomplete fix of CVE-2026-47211: untrusted project .env can still reach RCE via omitted execution-routing keys","modified":"2026-09-10T03:51:08.868868079Z","packages":[{"ecosystem":"PyPI","name":"ouroboros-ai","purl":"pkg:pypi/ouroboros-ai","ranges":["<0.42.1"],"fixed":["0.42.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}