Cyber Resilience

CVE-2026-33823

Critical

Published: 07 May 2026

Published
07 May 2026
Modified
08 May 2026
KEV Added
Patch
CVSS Score v3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
EPSS Score 0.0072 49.3th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-33823 is a critical-severity Improper Authorization (CWE-285) vulnerability in Microsoft Teams. Its CVSS base score is 9.6 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Messaging Applications (T1213.005); ranked at the 49.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Improper authorization in Microsoft Teams allows an authorized attacker to disclose information over a network.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1213.005 Messaging Applications Collection
Adversaries may leverage chat and messaging applications, such as Microsoft Teams, Google Chat, and Slack, to mine valuable information.
Why these techniques?

Improper authorization (CWE-285) in Microsoft Teams directly enables unauthorized access to messaging data over the network.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-21535Same product: Microsoft Teams
CVE-2025-26683Same vendor: Microsoft
CVE-2025-24053Same vendor: Microsoft
CVE-2025-21348Same vendor: Microsoft
CVE-2026-27912Same vendor: Microsoft
CVE-2025-49701Same vendor: Microsoft
CVE-2026-24305Same vendor: Microsoft
CVE-2025-21275Same vendor: Microsoft
CVE-2025-21400Same vendor: Microsoft
CVE-2025-64655Same vendor: Microsoft

Affected Assets

microsoft
teams
all versions

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-285

Documented procedures facilitate correct implementation and ongoing management of authorization decisions.

addresses: CWE-285

Periodic reviews identify and correct flaws in authorization decisions or enforcement.

addresses: CWE-285

The control's documentation requirement reduces improper authorization by ensuring only mission-justified actions bypass authentication.

addresses: CWE-285

Establishing permitted attributes and values, plus auditing changes, ensures authorization decisions are based on correctly managed policy data.

addresses: CWE-285

Explicitly mandates authorizing remote access types before permitting connections, directly mitigating improper authorization.

addresses: CWE-285

The control explicitly requires authorization of each wireless access type prior to permitting connections.

addresses: CWE-285

Mandating explicit authorization of mobile device connections reduces the risk of improper authorization decisions for system access.

addresses: CWE-285

Specifying access authorizations for each account and requiring approvals for account requests enforces proper authorization decisions.

References