Browser Server WebSocket origin validation bypass via unanchored regex (patch bypass of CVE-2026-40289 / GHSA-8x8f-54wf-vv92)

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-55536
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-25 16:16:54 UTC
Updated2026-08-28 23:17:06 UTC
DescriptionPraisonAI 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.

Risk And Classification

Primary CVSS: v3.1 9.1 CRITICAL from [email protected]

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

EPSS: 0.002910000 probability, percentile 0.211660000 (date 2026-08-28)

Problem Types: CWE-284 | CWE-625 | CWE-284 CWE-284: Improper Access Control | CWE-625 CWE-625: Permissive Regular Expression

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary9.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
3.1CNADECLARED9.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA MervinPraison PraisonAI affected < 4.6.58 Not specified

References

ReferenceSourceLinkTags
github.com/MervinPraison/PraisonAI/security/advisories/GHSA-6g6r-q6gw-w8fg 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com
github.com/MervinPraison/PraisonAI/commit/2f9677abb2ea68eab864ee8b6a828f... [email protected] github.com
github.com/MervinPraison/PraisonAI/releases/tag/v4.6.58 [email protected] github.com
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