CVE-2026-34939
Medium
Description
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.
SeverityMedium
CVSS6.5
Exploit probability—
ProductPraisonai
PublishedApr 3, 2026
First seenApr 3, 2026
Weakness typeCWE-1333CWE-1333
How to fix
Update
- praison praisonai4.5.90 or later
- praisonai4.5.90 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| praison praisonai | v < 4.5.90 | 4.5.90 |
| praisonaiPyPI | v < 4.5.90 | 4.5.90 |
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