CVE-2026-55536: CWE-284: Improper Access Control in MervinPraison PraisonAI
Description
CVE-2026-55536 is a critical improper access control vulnerability in MervinPraison's PraisonAI multi-agent teams system. Before version 4.6.58, the Browser Server's _handle_connection() function incorrectly validates Chrome extension origins using an unanchored regular expression, allowing extra trailing characters to bypass checks. This flaw permits unauthorized start_session commands and browser automation. The issue is fixed in PraisonAI version 4.6.58.
CVSS v3.1
Score 9.1critical
Affected software
MervinPraison
PraisonAI
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
PraisonAI versions prior to 4.6.58 contain an improper access control vulnerability (CWE-284) in the Browser Server's _handle_connection() method. The function uses re.match() with an unanchored regex pattern 'chrome-extension://[a-z0-9]{32}', which allows additional trailing characters to pass validation before websocket.accept(). This bypass enables unauthorized start_session commands and browser automation. The vulnerability is resolved in version 4.6.58.
Potential Impact
An attacker can bypass origin checks on Chrome extensions to initiate unauthorized start_session commands and automate browser actions without proper authorization. This leads to high confidentiality and integrity impacts, as indicated by the CVSS score of 9.1, but does not affect availability.
Mitigation Recommendations
Upgrade PraisonAI to version 4.6.58 or later, where the improper access control vulnerability is fixed. No other mitigation guidance is provided. Patch status is confirmed by the vendor's fix in version 4.6.58.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-16T23:01:04.074Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a8dba55acd9273b4965b676
Added to database: 08/25/2026, 15:52:53 UTC
Last enriched: 09/10/2026, 04:22:16 UTC
Last updated: 10/09/2026, 06:48:18 UTC
Views: 56
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