Cyber Resilience

CVE-2026-21229

High

Published: 10 February 2026

Published
10 February 2026
Modified
11 February 2026
KEV Added
—
Patch
—
CVSS Score v3.1 8.0 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0090 55.1th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-21229 is a high-severity Improper Input Validation (CWE-20) vulnerability in Microsoft Power Bi Report Server. Its CVSS base score is 8.0 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 44.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Deeper analysis

CVE-2026-21229 is an improper input validation vulnerability (CWE-20) in Power BI. Published on 2026-02-10T18:16:23.453, it carries a CVSS v3.1 base score of 8.0 (AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H), indicating high severity due to its potential for significant impact.

The vulnerability enables an authorized attacker with low privileges to execute arbitrary code over a network. Exploitation requires low attack complexity but user interaction, allowing the attacker to achieve high confidentiality, integrity, and availability impacts on the affected system.

Microsoft's advisory provides details on mitigation; see https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21229 for patches and guidance.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability details

Improper input validation in Power BI allows an authorized attacker to execute code over a network.

CWE(s)
CWE-20

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
Why these techniques?

Improper input validation enables remote arbitrary code execution in Power BI (network-accessible, low-priv attacker, user interaction), directly facilitating T1190 (public-facing app exploitation) and T1203 (client application exploitation for code exec).

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

CVEs Like This One

CVE-2026-40411Same vendor: Microsoft
CVE-2026-26106Same vendor: Microsoft
CVE-2026-20856Same vendor: Microsoft
CVE-2025-21344Same vendor: Microsoft
CVE-2026-32201Same vendor: Microsoft
CVE-2025-59228Same vendor: Microsoft
CVE-2026-26154Same vendor: Microsoft
CVE-2026-33844Same vendor: Microsoft
CVE-2026-20951Same vendor: Microsoft
CVE-2025-21273Same vendor: Microsoft

Affected Assets

microsoft
power bi report server
≤ 15.0.1120.113

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match
prevent

Directly requires systems to perform validation of all inputs to prevent exploitation of improper input validation vulnerabilities like CVE-2026-21229.

SI-2 Flaw Remediation good match
prevent

Mandates timely identification, reporting, and remediation of flaws such as this Power BI input validation vulnerability through patching.

SI-9 Information Input Restrictions partial match
prevent

Restricts the types and quantities of information inputs to reduce the attack surface for network-based input validation exploits.

References