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Vulnerability record · CVE-2026-39890 · published 8 April 2026

CVE-2026-39890: Praisonai deserialization of untrusted data vulnerability

Praison · Praisonai

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.

9.8 CVSS 3.1 Critical EPSS 0.81% · top 44.7% CWE-502 · Deserialization of untrusted data
9.8CVSS 3.1 base score
0.81%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
24 Jul 2026Last modified by NVD

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-32vr-5gcf-3pw2 Vendor Advisory
https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-32vr-5gcf-3pw2 Vendor Advisory

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Source: NIST National Vulnerability Database (record CVE-2026-39890), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.