Security readout for executives and security teams
Plain-English summary
Microsoft reports a high-severity Power BI Report Server flaw that could let an authorized attacker run code remotely over a network. The issue requires some user interaction and low privileges. The provided sources do not confirm active exploitation, but the potential business impact is serious because confidentiality, integrity, and availability are all rated high.
Executive priority
Treat this as a high-priority patching item for Power BI Report Server environments. It is not currently supported by the provided evidence as actively exploited, but remote code execution with high impact warrants prompt remediation and exposure review.
Technical view
CVE-2026-21229 is a CWE-20 improper input validation issue in Microsoft Power BI Report Server 1.6.0. CVSS 3.1 is 8.0 with network attack vector, low complexity, low privileges, required user interaction, unchanged scope, and high CIA impact. MSRC lists an official remediation path.
Likely exposure
Exposure is limited by the provided evidence to organizations running Microsoft Power BI Report Server 1.6.0. Risk is higher where the server is reachable across internal or external networks and accessible to many authorized users.
Exploitation context
The source bundle marks KEV as false and CVSS exploit maturity as unproven. No provided source confirms exploitation in the wild or public exploit availability. Exploitation is described as network-based, authenticated, and requiring user interaction.
Researcher notes
The public bundle does not include vulnerable endpoints, exploit mechanics, or fixed build details beyond MSRC’s patch reference. Validation should stay non-invasive and focus on asset/version confirmation, advisory alignment, and control review.
Mitigation direction
- Apply Microsoft’s official update for CVE-2026-21229 from the MSRC advisory.
- Prioritize internet-facing or broadly accessible Power BI Report Server instances.
- Restrict access to trusted users and networks until patched.
- Review Microsoft guidance for any version-specific remediation details.
- Document patch status for audit and vulnerability management tracking.
Validation and detection
- Inventory Power BI Report Server deployments and identify version 1.6.0.
- Confirm installed build and update status against the MSRC advisory.
- Verify access controls limit low-privileged user reach where possible.
- Check vulnerability scanner results for CVE-2026-21229 coverage.
- Review relevant server logs for unusual authenticated activity.
Public sources used
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.