CVE-2026-40289
📛 CVE Title
PraisonAI Browser Server allows unauthenticated WebSocket clients to hijack connected extension sessions
Description
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.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- GitHub_M
- CVSS severity
- CRITICAL
- CVSS score
- 9.1 / 10
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N- Effective score
- 9.1 / 10 CRITICAL source: CNA overview
- CWE(s)
-
CWE-306 - Reserved
- 2026-04-10
- Published
- 2026-04-14 05:05 UTC
- Last updated
- 2026-04-14 22:18 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/40xxx/CVE-2026-40289.json
- Linked Threat
- CVE-2026-40289 — PraisonAI Browser Server allows unauthenticated WebSocket clients to hijack connected extension sessions
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-04-14 04:17:12 UTC
- NVD last modified
- 2026-04-20 17:46:45 UTC
- NVD CVSS v3.1
- 9.1 / 10 CRITICAL source: security-advisories@github.com
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 5.2 / 10
- EPSS score
- 0.0005 (probability of exploitation in next 30 days)
- EPSS percentile
- 16.98% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD / KEV / EPSS data refreshed 2026-05-25 11:04 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-22211 - Assigner
- GitHub_M
- Published
- Apr 14, 2026, 3:05:05 AM
- Updated
- Apr 14, 2026, 8:18:37 PM
- EUVD base score (CVSS 3.1)
-
9.1 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - EUVD-reported EPSS
- 0.0700
- Vendors
- mervinpraison
- Products
-
praisonaiagents (< 1.5.140)PraisonAI (< 4.5.139)
ENISA description: 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.
Affected products (2)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| MervinPraison | PraisonAI |
< 4.5.139 (affected)
|
— |
| MervinPraison | praisonaiagents |
< 1.5.140 (affected)
|
— |
Affected products — CPE 2.3 (2) NVD
NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.
cpe:2.3:a:praison:praisonai:*:*:*:*:*:*:*:*cpe:2.3:a:praison:praisonaiagents:*:*:*:*:*:python:*:*
Vendor references (1)
References embedded in the original CVE record by the assigning CNA.
Web references (0)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
No web references attached yet.
NVD-tagged references (1)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-8x8f-54wf-vv92 security-advisories@github.com ExploitVendor Advisory
Indicators (1)
IOCs linked to the auto-promoted Threat row.
| Type | Value | VirusTotal | Attached |
|---|---|---|---|
| ipv4 |
0.0.0.0
|
2026-05-31 00:18 UTC)">not flagged | 2026-05-18 21:18 UTC |
Remediations (16)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:aviatrix.ai
The May 2026 Patch Tuesday update's high volume of critical vulnerabilities, despite the absence of zero-days, highlights the evolving threat landscape. Organizations must remain vigilant, as attackers may exploit these newly disclosed vulnerabilities. Prompt patching and proactive security measures are essential to safeguard systems against potential exploits.
2026-05-22 17:06 UTC -
web:carthageelectronics.com
Status: Actively exploited — CISA KEV listed — patch by May 12, 2026 What Happened On April 28, 2026 , CISA added CVE - 2026 -32202 to its Known Exploited Vulnerabilities (KEV) catalog with a federal remediation deadline of May 12, 2026 . This vulnerability is the result of an incomplete patch Microsoft released in February for CVE - 2026 -21510.
2026-05-22 17:06 UTC -
web:cyberpress.org
Microsoft has released its April 2026 Patch Tuesday updates, fixing 168 vulnerabilities across Windows, cloud, and application products, including one actively exploited zero-day in Microsoft SharePoint Server.
2026-05-22 17:06 UTC -
web:techcommunity.microsoft.com
We wanted to tell you how to address the Exchange Server May 2026 vulnerability CVE - 2026 -42897.
2026-05-22 17:06 UTC -
web:threatprotect.qualys.com
With Qualys Policy Audit's out-of-the-box mitigation or Compensatory Controls, which reduce the risk of a vulnerability being exploited because the remediation ( fix / patch ) cannot be done immediately, these security controls are not recommended by any industry standards, such as CIS and DISA-STIG.
2026-05-22 17:06 UTC -
web:www.bleepingcomputer.com
Today is Microsoft's May 2026 Patch Tuesday, with security updates for 120 flaws and no zero-days disclosed this month.
2026-05-22 17:06 UTC -
web:portal.msrc.microsoft.com
The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.
2026-05-22 02:45 UTC -
web:www.oracle.com
This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.
2026-05-22 02:45 UTC -
web:www.windowslatest.com
Windows 11 April 2026 update adds Narrator Copilot support, faster Settings, File Explorer fixes, and key security improvements.
2026-05-22 02:45 UTC -
web:zecurit.com
Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .
2026-05-22 02:45 UTC -
web:www.cisecurity.org
<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...
2026-05-22 02:45 UTC -
web:blog.qualys.com
May 2026's Patch Tuesday arrives with Microsoft addressing a fresh set of vulnerabilities across its ecosystem, reinforcing the ongoing need for timely patching in an increasingly threat-heavy…
2026-05-22 02:45 UTC -
web:www.crowdstrike.com
Microsoft's April 2026 Patch Tuesday addresses 164 CVEs , featuring 8 Critical vulnerabilities, one exploited zero-day, and one disclosed zero-day.
2026-05-22 02:45 UTC -
web:www.helpnetsecurity.com
Microsoft has marked May 2026 Patch Tuesday by releasing fixes for 120+ CVE -numbered vulnerabilities, none of which are actively exploited.
2026-05-22 02:45 UTC -
web:cybersecuritynews.com
Microsoft's May 2026 Patch Tuesday lands with a heavy enterprise focus, fixing 120 vulnerabilities across Windows, Office, Azure, developer tools, and Microsoft 365 apps, including 29 remote code execution (RCE) flaws rated Critical.
2026-05-22 02:45 UTC -
web:krebsonsecurity.com
Microsoft expects that exploitation is more likely. May's Patch Tuesday is a welcome respite from April, which saw Microsoft fix a near-record 167 security flaws.
2026-05-22 02:45 UTC
AI Forensic Analysis
Only Available for Registered Users. Sign in to view.
Raw JSON
The full cvelistV5 record. Download as CVE-2026-40289.json.
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-40289",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-14T20:18:27.623888Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-14T20:18:37.319Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "PraisonAI",
"vendor": "MervinPraison",
"versions": [
{
"status": "affected",
"version": "< 4.5.139"
}
]
},
{
"product": "praisonaiagents",
"vendor": "MervinPraison",
"versions": [
{
"status": "affected",
"version": "< 1.5.140"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 9.1,
"baseSeverity": "CRITICAL",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-306",
"description": "CWE-306: Missing Authentication for Critical Function",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-14T03:05:05.514Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-8x8f-54wf-vv92",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-8x8f-54wf-vv92"
}
],
"source": {
"advisory": "GHSA-8x8f-54wf-vv92",
"discovery": "UNKNOWN"
},
"title": "PraisonAI Browser Server allows unauthenticated WebSocket clients to hijack connected extension sessions"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-40289",
"datePublished": "2026-04-14T03:05:05.514Z",
"dateReserved": "2026-04-10T20:22:44.035Z",
"dateUpdated": "2026-04-14T20:18:37.319Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}