Vulnerability · Published Sep 8, 2026 · Assigned by microsoft
CVE-2026-84003Microsoft Authentication Library (MSAL) for Node.js Spoofing Vulnerability
High 7.4
In plain English
A high-severity security flaw in Microsoft Authentication Library from Microsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities).
Severity (CVSS 3.1)7.4High
Exploit odds (30 days)0.6%top 51.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Authentication bypass by capture-replay in Microsoft Authentication Library (MSAL) for Node.js allows an unauthorized attacker to perform spoofing over a network.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Microsoft Authentication Library | 1.0.0 – before 5.6.0 |
Weakness: CWE-294 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C
References
- Microsoft Authentication Library (MSAL) for Node.js Spoofing Vulnerability vendor-advisory, patch