CVE-2026-39890CRITICAL 9.8EPSS p43.1%
CVE-2026-39890CVE-2026-39890
Description
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.
Scoring
| CVSS 3.1 | 9.8 (CRITICAL) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 0.58% probability of exploitation · percentile 43.1% · 2026-06-18T12:00:27Z |
| Published | 2026-04-08 |
| Last modified | 2026-04-15 |
Underlying weaknesses· 1
References
1
| Type | Target | Confidence | Tier |
|---|---|---|---|
| Weakness | Deserialization of Untrusted Datacwe-502 | 0% | live |
Related by meaning· 6
Nearest entities by semantic similarity across the cs-graph corpus.