# [CRIT] [GHSA / CRITICAL] CVE-2026-47391: PraisonAI's unauthenticated A2A official example can reach real LLM-driven `eval()` tool execution

**Source:** GitHub Security Advisories
**Published:** 2026-05-29
**Article:** https://github.com/advisories/GHSA-vg22-4gmj-prxw

## Threat Profile

PraisonAI's unauthenticated A2A official example can reach real LLM-driven `eval()` tool execution

## Summary

The first-party PraisonAI A2A server example combines three behaviors into a remotely exploitable Critical chain:

1. The example exposes an A2A server without configuring `auth_token`.
2. The same example binds the server to `0.0.0.0`.
3. The example registers a `calculate(expression)` tool implemented with Python `eval(expression)`.

An unauthenticated network client can send a JSON-…

## Indicators of Compromise (high-fidelity only)

- **CVE:** `CVE-2026-47391`

## MITRE ATT&CK Techniques

- **T1190** — Exploit Public-Facing Application
- **T1204.002** — User Execution: Malicious File
- **T1059.006** — Command and Scripting Interpreter: Python
- **T1059.004** — Command and Scripting Interpreter: Unix Shell
- **T1133** — External Remote Services

## Kill chain phases observed

_(none detected from narrative keywords)_

## Recommended hunts

### Unauthenticated JSON-RPC POST to PraisonAI /a2a endpoint (CVE-2026-47391 exploit)

`UC_165_2` · phase: **delivery** · confidence: **Medium** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime values(Web.http_method) as method values(Web.url) as url values(Web.status) as status values(Web.src) as src_ip values(Web.dest) as dest_ip from datamodel=Web where Web.url="*/a2a*" Web.http_method="POST" Web.dest_port IN (8000,80,443,8080) by Web.src Web.dest Web.user_agent | `drop_dm_object_name(Web)` | search NOT src IN ("10.0.0.0/8","172.16.0.0/12","192.168.0.0/16","127.0.0.1") | where status=200 | rename src AS src_ip dest AS dest_ip
```

**Defender KQL:**
```kql
DeviceNetworkEvents
| where Timestamp > ago(7d)
| where ActionType in ("InboundConnectionAccepted","ConnectionSuccess")
| where LocalPort in (8000, 80, 443, 8080)
| where RemoteIPType == "Public"
| where InitiatingProcessFileName in~ ("python.exe","python3.exe","python3","python","uvicorn.exe","uvicorn")
   or InitiatingProcessCommandLine has_any ("a2a-server.py","a2a.py","praisonai","praisonaiagents")
| project Timestamp, DeviceName, RemoteIP, RemotePort, LocalIP, LocalPort,
          InitiatingProcessFileName, InitiatingProcessCommandLine,
          InitiatingProcessAccountName, InitiatingProcessFolderPath, ReportId
| order by Timestamp desc
```

### Suspicious child process spawned by PraisonAI uvicorn/python A2A server (eval() RCE evidence)

`UC_165_3` · phase: **exploit** · confidence: **High** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime values(Processes.process) as cmdline values(Processes.process_name) as child_name values(Processes.parent_process_name) as parent_name values(Processes.parent_process) as parent_cmd values(Processes.user) as user from datamodel=Endpoint.Processes where (Processes.parent_process_name IN ("python","python3","python.exe","python3.exe","uvicorn","uvicorn.exe") AND Processes.parent_process IN ("*a2a-server.py*","*praisonai*","*praisonaiagents*","*a2a.py*")) (Processes.process_name IN ("sh","bash","dash","zsh","cmd.exe","powershell.exe","pwsh.exe","curl","wget","nc","ncat","socat","whoami","id","uname","hostname","cat","env","printenv") OR Processes.process IN ("*os.system*","*subprocess.*","*__import__*","*compile(*","*exec(*","*open('/etc/passwd*","*open(\"/etc/passwd*")) by Processes.dest Processes.parent_process_name Processes.parent_process Processes.process_name Processes.process Processes.user | `drop_dm_object_name(Processes)`
```

**Defender KQL:**
```kql
DeviceProcessEvents
| where Timestamp > ago(7d)
| where InitiatingProcessFileName in~ ("python.exe","python3.exe","python","python3","uvicorn.exe","uvicorn")
| where InitiatingProcessCommandLine has_any ("a2a-server.py","praisonai","praisonaiagents","a2a.py")
   or InitiatingProcessParentFileName in~ ("uvicorn","uvicorn.exe")
| where FileName in~ ("sh","bash","dash","zsh","cmd.exe","powershell.exe","pwsh.exe",
                     "curl","curl.exe","wget","wget.exe","nc","ncat","socat",
                     "whoami","whoami.exe","id","uname","hostname","hostname.exe",
                     "cat","env","printenv","net.exe","net1.exe","ipconfig.exe","ifconfig")
   or ProcessCommandLine has_any ("/etc/passwd","/etc/shadow","~/.aws/credentials","~/.ssh/id_",
                                  "GEMINI_API_KEY","OPENAI_API_KEY","ANTHROPIC_API_KEY",
                                  "official-a2a-example-real-llm-canary")
| project Timestamp, DeviceName, AccountName,
          ParentImage = InitiatingProcessFolderPath,
          ParentCmd = InitiatingProcessCommandLine,
          ChildImage = FolderPath,
          ChildCmd = ProcessCommandLine,
          SHA256, ReportId
| order by Timestamp desc
```

### PraisonAI A2A example server started with vulnerable 0.0.0.0 bind and no auth_token

`UC_165_4` · phase: **install** · confidence: **Medium** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime values(Processes.process) as cmdline values(Processes.parent_process) as parent_cmd values(Processes.user) as user from datamodel=Endpoint.Processes where Processes.process_name IN ("python","python3","python.exe","python3.exe","uvicorn","uvicorn.exe") AND (Processes.process IN ("*a2a-server.py*","*praisonaiagents*a2a*","*A2A(*") OR Processes.process IN ("*uvicorn.run*0.0.0.0*8000*","*--host*0.0.0.0*")) by Processes.dest Processes.process_name Processes.process Processes.parent_process_name Processes.user | `drop_dm_object_name(Processes)` | search cmdline="*a2a*" OR cmdline="*praisonai*"
```

**Defender KQL:**
```kql
DeviceProcessEvents
| where Timestamp > ago(30d)
| where FileName in~ ("python.exe","python3.exe","python","python3","uvicorn.exe","uvicorn")
| where ProcessCommandLine has_any ("a2a-server.py","praisonaiagents","praisonai") 
     or (ProcessCommandLine has "A2A" and ProcessCommandLine has "serve")
| extend BindsAllInterfaces = ProcessCommandLine has_any ("0.0.0.0","--host 0.0.0.0")
| extend ConfiguresAuth = ProcessCommandLine has_any ("auth_token","AUTH_TOKEN")
| where BindsAllInterfaces == true or ConfiguresAuth == false
| summarize FirstSeen = min(Timestamp), LastSeen = max(Timestamp), Hits = count(),
            AnyCmd = any(ProcessCommandLine), AnyParent = any(InitiatingProcessCommandLine)
            by DeviceName, AccountName, FileName
| order by LastSeen desc
```

### Article-specific behavioural hunt — [GHSA / CRITICAL] CVE-2026-47391: PraisonAI's unauthenticated A2A official examp

`UC_165_1` · phase: **exploit** · confidence: **High**

**Splunk SPL (CIM):**
```spl
``` Article-specific bespoke detection — [GHSA / CRITICAL] CVE-2026-47391: PraisonAI's unauthenticated A2A official examp ```
| tstats `summariesonly` count earliest(_time) AS firstTime latest(_time) AS lastTime
    from datamodel=Endpoint.Processes
    where (Processes.process_name IN ("server.py","official-a2a-example-real-llm-canary.py","a2a-server.py"))
    by Processes.dest, Processes.user, Processes.process_name,
       Processes.process, Processes.parent_process_name, Processes.process_path
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| append [
| tstats `summariesonly` count
    from datamodel=Endpoint.Filesystem
    where Filesystem.action IN ("created","modified")
      AND (Filesystem.file_path="*/home/employees/fox-linux-qa-002/work/inbox/PraisonAI/examples/python/a2a/a2a-server.py*" OR Filesystem.file_path="*/home/employees/fox-linux-qa-002/work/out/official-a2a-example-real-llm-canary.txt*" OR Filesystem.file_path="*/usr/bin/env*" OR Filesystem.file_path="*/home/employees/fox-linux-qa-002/work/out/official-a2a-example-http-eval-canary.txt*" OR Filesystem.file_name IN ("server.py","official-a2a-example-real-llm-canary.py","a2a-server.py"))
    by Filesystem.dest, Filesystem.user, Filesystem.process_name,
       Filesystem.file_path, Filesystem.file_name
| `drop_dm_object_name(Filesystem)`
]
```

**Defender KQL:**
```kql
// Article-specific bespoke detection — [GHSA / CRITICAL] CVE-2026-47391: PraisonAI's unauthenticated A2A official examp
// Hunts the actual binaries / paths / commandline fragments named
// in the article instead of a generic technique-class template.
DeviceProcessEvents
| where Timestamp > ago(30d)
| where (FileName in~ ("server.py", "official-a2a-example-real-llm-canary.py", "a2a-server.py"))
| project Timestamp, DeviceName, AccountName, FileName,
          FolderPath, ProcessCommandLine,
          InitiatingProcessFileName, InitiatingProcessCommandLine
| order by Timestamp desc

// File-creation events for the named binaries / paths
DeviceFileEvents
| where Timestamp > ago(30d)
| where ActionType in ("FileCreated","FileModified")
| where (FolderPath has_any ("/home/employees/fox-linux-qa-002/work/inbox/PraisonAI/examples/python/a2a/a2a-server.py", "/home/employees/fox-linux-qa-002/work/out/official-a2a-example-real-llm-canary.txt", "/usr/bin/env", "/home/employees/fox-linux-qa-002/work/out/official-a2a-example-http-eval-canary.txt") or FileName in~ ("server.py", "official-a2a-example-real-llm-canary.py", "a2a-server.py"))
| project Timestamp, DeviceName, AccountName, FolderPath,
          FileName, ActionType, InitiatingProcessFileName,
          InitiatingProcessCommandLine
| order by Timestamp desc
```

### IOC-driven hunts (use shared templates)

These are standard IOC-substitution hunts — the canonical SPL and KQL live once in [`_TEMPLATES.md`](../_TEMPLATES.md), so we don't repeat the same boilerplate on every CVE / hash / network-IOC briefing.

- **Asset exposure — vulnerability matches article CVE(s)** ([template](../_TEMPLATES.md#asset-exposure)) — phase: **recon**, confidence: **High**
  - CVE(s): `CVE-2026-47391`


## Why this matters

Severity classified as **CRIT** based on: CVE present, 5 use case(s) fired, 5 technique(s) inferred. Read the full article for actor attribution, tooling details, and any defanged IOCs in the body that aren't visible in the RSS summary.