What is CVE-2024-21390?

CVE-2024-21390 is a high-severity vulnerability in Microsoft Authenticator, classified under Improper Authentication. CVSS score: 7.1/10. Published 2024-03-12.

How severe is CVE-2024-21390?

High severity. CVSS v3 base score is 7.1 out of 10.

Is CVE-2024-21390 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Auth bypass in Microsoft Authenticator

CVE-2024-21390

Microsoft Authenticator Elevation of Privilege Vulnerability

Vulnerability class: Broken Authentication

Published 2024-03-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.013 (68.7th percentile), scored 2026-10-03.

Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 68.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000

Affected products

Microsoft Authenticator
Microsoft Authenticator — versions 1.0.0

Weakness classification (CWE)

CWE-287 — Improper Authentication

Public proof-of-concept exploits

NaInSec/CVE-LIST

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21390 (vendor-advisory, Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2024-21390?: CVE-2024-21390 is a high-severity vulnerability in Microsoft Authenticator, classified under Improper Authentication. CVSS score: 7.1/10. Published 2024-03-12.
How severe is CVE-2024-21390?: High severity. CVSS v3 base score is 7.1 out of 10.
Is CVE-2024-21390 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.