What is CVE-2026-21535?

CVE-2026-21535 is a high-severity vulnerability in Microsoft Teams, classified under Improper Access Control. CVSS score: 8.2/10. Published 2026-02-19.

How severe is CVE-2026-21535?

High severity. CVSS v3 base score is 8.2 out of 10.

Vulnerability in Microsoft Teams

CVE-2026-21535

Improper access control in Microsoft Teams allows an unauthorized attacker to disclose information over a network.

EPSS: 0.001 (25.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N/E:U/RL:O/RC:C.

Affected products

Microsoft Teams

Weakness classification (CWE)

CWE-284 — Improper Access Control

References

Microsoft Teams Information Disclosure Vulnerability (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-21535?: CVE-2026-21535 is a high-severity vulnerability in Microsoft Teams, classified under Improper Access Control. CVSS score: 8.2/10. Published 2026-02-19.
How severe is CVE-2026-21535?: High severity. CVSS v3 base score is 8.2 out of 10.