CVE-2026-84003 Microsoft Authentication Library (MSAL) for Node.js - Authentication Bypass

Microsoft Authentication Library (MSAL) for Node.js contains an authentication bypass caused by capture-replay attacks, letting unauthorized attackers perform spoofing over a network, exploit requires network access.

CVSS base score 7.4 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.60% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Authentication Bypass
Impact
Broken Authentication
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Published
8 September 2026
Updated
15 October 2026
Weakness
CWE-294

Vendor fix

Update to the latest version of Microsoft Authentication Library (MSAL) for Node.js.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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