CVE-2026-34939
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk33th percentile - higher than 33% of all known CVEs
Summary
Vulnerability in PraisonAI before version 4.5.90, where MCPToolIndex.search_tools() compiles a caller-supplied string directly as a Python regular expression without 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.
Risk Assessment
An attacker can remotely cause a denial of service (DoS) by sending a malicious regex, rendering the PraisonAI system unavailable.
Recommendation
Update PraisonAI to version 4.5.90.
Original NVD description (English source)
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.