NVD / CVE Program· CNA GitHub_M

CVE-2026-40289: PraisonAI Browser Server allows unauthenticated WebSocket clients to hijack connected extension sessions

Noroxi assessment

Priority: Monitor (action score 36/100)

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: 0.42% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: praisonai (PyPI) 4.5.139; praisonaiagents (PyPI) 1.5.140.

Low priority for now. Upgrade to praisonai (PyPI) 4.5.139; praisonaiagents (PyPI) 1.5.140 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. In versions below 4.5.139 of PraisonAI and 1.5.140 of praisonaiagents, the browser bridge (praisonai browser start) is vulnerable to unauthenticated remote session hijacking due to missing authentication and a bypassable origin check on its /ws WebSocket endpoint. The server binds to 0.0.0.0 by default and only validates the Origin header when one is present, meaning any non-browser client that omits the header is accepted without restriction. An unauthenticated network attacker can connect, send a start_session message, and the server will route it to the first idle browser-extension WebSocket (effectively hijacking that session) and then broadcast all resulting automation actions and outputs back to the attacker. This enables unauthorized remote control of connected browser automation sessions, leakage of sensitive page context and automation results, and misuse of model-backed browser actions in any environment where the bridge is network-reachable. This issue has been fixed in versions 4.5.139 of PraisonAI and 1.5.140 of praisonaiagents.

CriticalCVSS 9.1 · v3.1—No exploit Fix available

Published: Apr 14, 2026
Updated: Oct 26, 2026
EPSS: 0.4% · 36th percentile
CWE: CWE-306

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 36 / 40 · 9.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.4%

CISA SSVC decision

Exploitation: proof of concept
Automatable: yes
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 9.1; 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

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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.

Vendor	Product	CPE
praison	praisonai	cpe:2.3:a:praison:praisonai
praison	praisonaiagents	cpe:2.3:a:praison:praisonaiagents

Affected versions

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

praison praisonaibefore 4.5.139
praison praisonaiagentsbefore 1.5.140

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
- < 4.5.139affected
MervinPraison praisonaiagents
- < 1.5.140affected

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
PyPI	praisonai	before 4.5.139	4.5.139
PyPI	praisonaiagents	before 1.5.140	1.5.140

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-2026-40287Apr 14, 2026 · PraisonAI has RCE via Automatic tools.py Import
33Monitor
← EarlierCVE-2026-40288Apr 14, 2026 · PraisonAI: Critical RCE via `type: job` workflow YAML
39Monitor
Later →CVE-2026-40313Apr 14, 2026 · PraisonAI: ArtiPACKED Vulnerability via GitHub Actions Credential Persistence
36Monitor

Remediation

Which version to upgrade to

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

Product / package	Fixed version	Source
PyPI:praisonai	4.5.139	Package registry (OSV)
PyPI:praisonaiagents	1.5.140	Package 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-2026-4433824 days apartPraisonAI ships and generates a legacy API server with authentication disabled by default, allowing unauthenticated workflow execution
39Monitor
CVE-2026-3495211 days apartPraisonAI: Missing Authentication in WebSocket Gateway
36Monitor

Chain candidates

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

CVE-2026-398916 days apartPraisonAI has a Template Injection in Agent Tool Definitions
35Monitor
CVE-2026-393067 days apartPraisonAI recipe registry pull path traversal writes files outside the chosen output directory
29Monitor
CVE-2026-403150 days apartPraisonAI: SQLiteConversationStore didn't validate table_prefix when constructing SQL queries
28Monitor
CVE-2026-393087 days apartPraisonAI recipe registry publish path traversal allows out-of-root file write
28Monitor

Bug bounty scope

No known public program.

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

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: None

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS vector

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

nvd-secondary

Root cause

A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”

The bug in code

The whole CWE-306 class

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

Vulnerable

1// Added for the support team
2app.post("/maintenance/reset", resetDevice);

Fixed

1if (config.maintenanceEnabled) {
2  app.post(
3    "/maintenance/reset",
4    requireSession, requireRole("admin"), resetDevice
5  );
6}

Attack context

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

Attack patterns (CAPEC)

ATT&CK techniques

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Change log

Fix✗ → ✓Sep 28, 2026, 10:48 PM UTC

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