CVE-2026-42073

Description

OpenClaude MCP OAuth Callback: State Check Bypass via error Param Leads to DoS

Overview

State

—

Assigner (CNA)

—

CVSS severity

medium

CVSS score

6.5 / 10

CVSS vector

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

Effective score

6.5 / 10 MEDIUM source: CNA overview

CWE(s)

—

Reserved

—

Published

—

Last updated

—

Source

https://www.tenable.com/cve/CVE-2026-42073

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-2026-33973

Assigner

GitHub_M

Published

Jun 2, 2026, 3:38:53 PM

Updated

Jun 2, 2026, 5:40:55 PM

EUVD base score (CVSS 3.1)

6.5 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EUVD-reported EPSS

0.2200

Vendors

Gitlawb

Products

openclaude (< 0.5.1)

Aliases

GHSA-c73c-x77g-854r

ENISA description: OpenClaude is an open-source coding-agent command line interface for cloud and local model providers. Prior to version 0.5.1, the OpenClaude MCP authentication flow starts a temporary local HTTP server to handle OAuth callbacks. To prevent CSRF attacks, the server validates a state parameter against an internally stored value. However, due to a logic flaw in the order of conditionals, an attacker can completely bypass this check and force the server to shut down — without knowing the state value at all. This issue has been patched in version 0.5.1.

Vendor references (0)

References embedded in the original CVE record by the assigning CNA.

None in the CVE record.

Web references (6)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

• https://www.first.org/epss/ tenable:www.first.org
• https://github.com/Gitlawb/openclaude/commit/739b8d1f40fde0e401a5cbd2b9a55d88bd5124ad tenable:github.com
• https://github.com/Gitlawb/openclaude/releases/tag/v0.5.1 tenable:github.com
• https://github.com/Gitlawb/openclaude/security/advisories/GHSA-c73c-x77g-854r tenable:github.com
• https://nvd.nist.gov/vuln/detail/CVE-2026-42073 tenable:nvd.nist.gov
• https://www.cve.org/CVERecord?id=CVE-2026-42073 tenable:www.cve.org

• Microsoft and Adobe Patch Tuesday, March 2026 Security Update Review
  web:blog.qualys.com

  Microsoft has rolled out its March 2026 Patch Tuesday updates, delivering a fresh batch of security fixes designed to keep Windows environments protected from emerging threats.

  2026-05-26 03:07 UTC
• Security Advisory Bulletin 064 | Ubiquiti Community
  web:community.ui.com

  Published: May 21, 2026 Updated: May 22, 2026 Version: 1.1 Revision: 1.1 Summary 1 of 5 A malicious actor with access to the network and high privileges could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection. Affected Products: UniFi OS Server (Version 5.0.6 and earlier) Mitigation : Update your UniFi OS Server to Version 5.0.8 or later ...

  2026-05-26 03:07 UTC
• Microsoft's March 2026 security update addresses 83 vulnerabilities
  web:cyberinsider.com

  Microsoft fixes 83 vulnerabilities in Windows 11 with the March 2026 Patch Tuesday update, including two publicly disclosed zero-day flaws.

  2026-05-26 03:07 UTC
• CISA Warns of Exploited Microsoft Defender 0-Day Flaws
  web:cyberpress.org

  The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .

  2026-05-26 03:07 UTC
• Microsoft Patch Tuesday March 2026 - 78 Vulnerabilities Fixed ...
  web:cybersecuritynews.com

  Microsoft released its March 2026 Patch Tuesday security update on March 10, 2026 , addressing 78 vulnerabilities across Windows, Microsoft Office, Azure, SQL Server, and .NET. The update includes one actively exploited zero-day vulnerability and multiple Critical-rated flaws demanding immediate attention from security teams. The most urgent fix this month is CVE - 2026 -21262, the sole zero-day ...

  2026-05-26 03:07 UTC
• March 13, 2026—Hotpatch KB5084597 (OS Builds 26200.7982 and 26100.7982 ...
  web:support.microsoft.com

  This update for Windows 11, version 25H2 and 24H2 (KB5084597) incudes security improvements. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained. For information on Windows update terminology, see the different types of Windows software updates. To view the ...

  2026-05-26 03:07 UTC
• SAP Security Patch Day - March 2026
  web:support.sap.com

  SAP security patch day bulletin

  2026-05-26 03:07 UTC
• CISA Adds One Known Exploited Vulnerability to Catalog
  web:www.cisa.gov

  Although BOD 22-01 only applies to FCEB agencies, CISA strongly urges all organizations to reduce their exposure to cyberattacks by prioritizing timely remediation of KEV Catalog vulnerabilities as part of their vulnerability management practice. CISA will continue to add vulnerabilities to the catalog that meet the specified criteria.

  2026-05-26 03:07 UTC
• Oracle Critical Patch Update Advisory - April 2026
  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.

  2026-05-26 03:07 UTC
• I tested Windows 11 March 2026 Updates: Everything new ... - Windows Latest
  web:www.windowslatest.com

  Windows 11 March 2026 Patch Tuesday update adds Emoji 16.0, Sysmon, network speed test, reliability improvements, and security fixes.

  2026-05-26 03:07 UTC

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