Security readout for executives and security teams
Plain-English summary
An authenticated attacker could exploit improper input validation in Microsoft Power BI Report Server to run code remotely. Successful exploitation could compromise sensitive reports, alter data, and disrupt service. The issue is rated high severity, but the available evidence does not establish active exploitation.
Executive priority
Treat as a high-priority remediation, especially for externally reachable or business-critical report servers. Require rapid inventory, official update deployment, and verification. Emergency incident response is not justified solely by the supplied evidence because active exploitation has not been established.
Technical view
CVE-2026-21229 is a CWE-20 input-validation flaw affecting the listed Power BI Report Server 1.6.0. The CVSS 3.1 vector indicates network reachability, low attack complexity, low privileges, required user interaction, unchanged scope, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely where Power BI Report Server 1.6.0 is deployed, reachable by an authorized attacker, and supports the required user interaction. Internet or broadly network-accessible installations warrant faster review. The supplied sources do not identify affected configurations beyond the listed version.
Exploitation context
The attacker must already have low-level authorization and must obtain user interaction. No CISA KEV listing or supplied source confirms exploitation in the wild. Public exploit availability is not established by the source bundle.
Researcher notes
The public bundle identifies improper input validation but provides no vulnerable component, input path, exploit primitive, indicators, or detailed attack sequence. Validate exposure defensively against the Microsoft advisory; do not infer that other Power BI products or versions are affected.
Mitigation direction
- Identify Power BI Report Server 1.6.0 installations and their network exposure.
- Review the Microsoft advisory and apply its official security update promptly.
- Restrict server access to trusted users and networks until remediation is verified.
- Monitor authenticated activity for unusual report-server actions or code-execution indicators.
Validation and detection
- Confirm deployed Power BI Report Server versions through authoritative asset records.
- Verify the Microsoft security update is installed on every affected server.
- Review access controls and identify accounts capable of reaching affected services.
- Inspect relevant server and security logs for suspicious authenticated activity.
- Confirm remediated systems remain operational and reporting functions behave normally.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-20: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-21229 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C2.15.9microsoftVulnerability scoring details
Base CVSS 3.1 score
8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- Power BI Remote Code Execution VulnerabilityCVE reference, microsoft · vendor-advisory, patch
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.