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NVD / CVE Program· CNA GitHub_M

CVE-2026-40159: PraisonAI Exposes Sensitive Environment Variable via Untrusted MCP Subprocess Execution

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.18% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: MervinPraison PraisonAI 4.5.128.

Low priority for now. Upgrade to MervinPraison PraisonAI 4.5.128 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

PraisonAI is a multi-agent teams system. Prior to 4.5.128, PraisonAI’s MCP (Model Context Protocol) integration allows spawning background servers via stdio using user-supplied command strings (e.g., MCP("npx -y @smithery/cli ...")). These commands are executed through Python’s subprocess module. By default, the implementation forwards the entire parent process environment to the spawned subprocess. As a result, any MCP command executed in this manner inherits all environment variables from the host process, including sensitive data such as API keys, authentication tokens, and database credentials. This behavior introduces a security risk when untrusted or third-party commands are used. In common scenarios where MCP tools are invoked via package runners such as npx -y, arbitrary code from external or potentially compromised packages may execute with access to these inherited environment variables. This creates a risk of unintended credential exposure and enables potential supply chain attacks through silent exfiltration of secrets. This vulnerability is fixed in 4.5.128.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Apr 10, 2026
Updated
Oct 26, 2026
EPSS
0.1% · 7th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
5.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
praisonpraisonai

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • praison praisonaibefore 4.5.128

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • MervinPraison PraisonAI

    • < 4.5.128affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
PyPIpraisonaibefore 4.5.1284.5.128

Same product

praison: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-40114PraisonAI has Server-Side Request Forgery via Unvalidated webhook_url in Jobs API
    40Plan
  • CVE-2026-39305Arbitrary File Write / Path Traversal in Action Orchestrator
    40Plan
  • CVE-2026-34955PraisonAI: Sandbox Escape via shell=True and Bypassable Blocklist in SubprocessSandbox
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-40157Apr 10, 2026 · PraisonAI affected by arbitrary file write via path traversal in `praisonai recipe unpack`
    37Monitor
  • ← EarlierCVE-2026-40158Apr 10, 2026 · PraisonAI has Improper Control of Generation of Code ('Code Injection') and Protection Mechanism Failure in praisonai
    31Monitor
  • Later →CVE-2026-40287Apr 14, 2026 · PraisonAI has RCE via Automatic tools.py Import
    33Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
MervinPraison PraisonAI4.5.128 · descriptionVendor (CNA)
PyPI:praisonai4.5.128Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-398892 days apartPraisonAI has Unauthenticated SSE Event Stream Exposes All Agent Activity in A2U Server
    30Monitor
  • CVE-2026-401511 days apartPraisonAI Affected by Unauthenticated Information Disclosure of Agent Instructions via /api/agents in AgentOS
    21Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

nvd-secondary

Root cause

The extension requests broader permissions than its function needs and sends the data it collects out for purposes beyond its stated function.

The bug in code

The whole CWE-200 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

json
{  "permissions": ["tabs", "<all_urls>"],  "background": { "service_worker": "analytics.js" }}

Fixed

json
{  "permissions": ["activeTab"],  "host_permissions": ["https://yildiz.example/*"]}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records