CVE-2026-84003: CWE-294: Authentication Bypass by Capture-replay in Microsoft Microsoft Authentication Library
Authentication bypass by capture-replay in Microsoft Authentication Library (MSAL) for Node.js allows an unauthorized attacker to perform spoofing over a network.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-84003) involves an authentication bypass caused by capture-replay attacks in Microsoft Authentication Library (MSAL) for Node.js. Specifically, version 1.0.0 is affected. The flaw allows an unauthorized attacker to spoof authentication credentials by replaying captured network authentication data. Microsoft has published an official fix to remediate this issue.
Potential Impact
Successful exploitation of this vulnerability allows an attacker to bypass authentication mechanisms in MSAL for Node.js, potentially gaining unauthorized access to resources or services that rely on this library for authentication. The confidentiality and integrity of the affected system can be compromised, but availability is not impacted.
Mitigation Recommendations
An official fix is available from Microsoft. Users of MSAL for Node.js version 1.0.0 should apply the vendor-provided patch as soon as possible. Refer to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-84003 for detailed remediation instructions.
CVE-2026-84003: CWE-294: Authentication Bypass by Capture-replay in Microsoft Microsoft Authentication Library
Description
Authentication bypass by capture-replay in Microsoft Authentication Library (MSAL) for Node.js allows an unauthorized attacker to perform spoofing over a network.
CVSS v3.1
Score 7.4high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-84003) involves an authentication bypass caused by capture-replay attacks in Microsoft Authentication Library (MSAL) for Node.js. Specifically, version 1.0.0 is affected. The flaw allows an unauthorized attacker to spoof authentication credentials by replaying captured network authentication data. Microsoft has published an official fix to remediate this issue.
Potential Impact
Successful exploitation of this vulnerability allows an attacker to bypass authentication mechanisms in MSAL for Node.js, potentially gaining unauthorized access to resources or services that rely on this library for authentication. The confidentiality and integrity of the affected system can be compromised, but availability is not impacted.
Mitigation Recommendations
An official fix is available from Microsoft. Users of MSAL for Node.js version 1.0.0 should apply the vendor-provided patch as soon as possible. Refer to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-84003 for detailed remediation instructions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-09-01T01:16:35.985Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-84003","vendor":"Microsoft"}]
Threat ID: 6aa0457cacd9273b49fbdf81
Added to database: 09/08/2026, 17:27:24 UTC
Last enriched: 09/08/2026, 17:37:18 UTC
Last updated: 09/09/2026, 01:23:14 UTC
Views: 9
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