Quick answers
- Is CVE-2026-84003 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-84003 being exploited in the wild.
- How severe is CVE-2026-84003?
- High severity, with a CVSS score of 7.4, published 8 September 2026.
- Which products and versions are affected?
- Microsoft Authentication Library (MSAL) for Node.js.
- Is there a fix for CVE-2026-84003?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-84003 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-84003?
- Check whether you run Microsoft Authentication Library (MSAL) for Node.js or Microsoft Azure\. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is an authentication bypass in MSAL for Node.js that exploits capture-replay attack techniques. An attacker can intercept and replay authentication tokens or credentials to bypass the authentication mechanism and assume the identity of a legitimate user. The attack is network-based and does not require prior authentication or special privileges. This vulnerability allows an attacker to spoof user identity and gain unauthorized access to protected resources. A patch is expected to be available from Microsoft.
Affected products
- Microsoft Authentication Library (MSAL) for Node.js
Timeline
- 2026-09-08: disclosed