CVE-2026-39890CWE-502

PraisonAI Affected by Remote Code Execution via YAML Deserialization in Agent Definition Loading

Critical · published April 8, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
56.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00812 · 56.5th percentile
Weakness
CWE-502 · Deserialization of Untrusted Data
Published
2026-04-08T20:45Z
EPSS history
Timeline
  • 08 APR 20:45Z
    PraisonAI Affected by Remote Code Execution via YAML Deserialization in Agent Definition Loading
    cvelistv5