{"id":"CVE-2026-39890","aliases":["GHSA-32vr-5gcf-3pw2","PYSEC-2026-462"],"url":"https://o3.security/vulnerability/CVE-2026-39890","summary":"PraisonAI Affected by Remote Code Execution via YAML Deserialization in Agent Definition Loading","details":"PraisonAI is a multi-agent teams system. Prior to 4.5.115, the AgentService.loadAgentFromFile method uses the js-yaml library to parse YAML files without disabling dangerous tags (such as !!js/function and !!js/undefined). This allows an attacker to craft a malicious YAML file that, when parsed, executes arbitrary JavaScript code. An attacker can exploit this vulnerability by uploading a malicious agent definition file via the API endpoint, leading to remote code execution (RCE) on the server. This vulnerability is fixed in 4.5.115.","published":"2026-04-08T20:45:30.928Z","modified":"2026-08-07T11:50:45.698205710Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"praisonai","fixedVersion":"4.5.115"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39890.json"},{"type":"ADVISORY","url":"https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-32vr-5gcf-3pw2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39890"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:50:45.698205710Z"}}