CVE-2026-34939: Praison Praisonai

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

PraisonAI is a multi-agent teams system. Prior to version 4.5.90, MCPToolIndex.search_tools() compiles a caller-supplied string directly as a Python regular expression with no validation, sanitization, or timeout. A crafted regex causes catastrophic backtracking in the re engine, blocking the Python thread for hundreds of seconds and causing a complete service outage. This issue has been patched in version 4.5.90.

Affected products

• Praison Praisonai: before 4.5.90 (fixed in 4.5.90)

Published 2026-04-03. Last modified 2026-07-24.