CVE-2026-34939CWE-1333

PraisonAI: ReDoS via Unvalidated User-Controlled Regex in MCPToolIndex.search_tools()

Medium · published April 3, 2026

CVSS v3.1
6.5
EPSS
0%
Percentile
38.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00448 · 38.0th percentile
Weakness
CWE-1333 · Inefficient Regular Expression Complexity
Published
2026-04-03T22:52Z
EPSS history
Timeline
  • 03 APR 22:52Z
    PraisonAI: ReDoS via Unvalidated User-Controlled Regex in MCPToolIndex.search_tools()
    cvelistv5