CVE-2026-55536
Received Received - Intake

Browser Origin Validation Bypass in PraisonAI

Publication date: 2026-08-25

Last updated on: 2026-08-25

Assigner: GitHub, Inc.

Description
PraisonAI is a multi-agent teams system. Prior to praisonai 4.6.58, Browser Server _handle_connection() checks Chrome extension origins with re.match() and the unanchored expression chrome-extension://[a-z0-9]{32}. Extra trailing characters pass before websocket.accept(), allowing start_session commands and unauthorized browser automation. This issue is fixed in version 4.6.58.

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Meta Information

Published
2026-08-25
Last Modified
2026-08-25
Generated
2026-08-25
AI Q&A
2026-08-25
EPSS Evaluated
N/A
NVD
CVE-2026-55536
EUVD
EUVD-2026-65545

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
mervinpraison praisonai From 4.6.58 (exc)
praisonai praisonai 4.6.58

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-625 The product uses a regular expression that does not sufficiently restrict the set of allowed values.
CWE-284 The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

Attack-Flow Graph

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Executive Summary

This is a critical authentication bypass vulnerability in PraisonAI's browser server. It allows attackers to bypass WebSocket origin validation using an unanchored regular expression. The flaw stems from using re.match() which only checks the start of the string without enforcing a strict 32-character length for Chrome extension IDs. This enables attackers to send malicious start_session commands and perform unauthorized browser automation.

Detection Guidance

Check if PraisonAI is running on port 8765 by running netstat -tulnp | grep 8765 or ss -tulnp | grep 8765. Inspect browser/server.py for the use of re.match() with the pattern chrome-extension://[a-z0-9]{32} and verify if it is properly validating the full string.

Impact Analysis

Attackers can exploit this to perform arbitrary browser automation such as stealing cookies, capturing screenshots, or executing actions on authenticated sites like banking or email platforms. Exploitation requires local access or remote configuration and can lead to unauthorized data access or account takeover.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating confidentiality requirements in GDPR and HIPAA. Organizations using affected versions may face compliance violations, data breach notifications, and potential regulatory penalties due to insufficient access controls.

Mitigation Strategies

Upgrade PraisonAI to version 4.6.58 or later. Replace re.match() with re.fullmatch() in browser/server.py and enforce strict 32-character Chrome extension ID validation. Disable remote access if not needed by setting PRAISONAI_BROWSER_ALLOW_REMOTE=false.

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