# CVE-2021-26859: Microsoft Power BI Information Disclosure Vulnerability

> An attacker can exploit this vulnerability in Microsoft Power BI Report Server to disclose sensitive information.

- **Severity:** High 7.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N/E:U/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Mar 2021
- **Updated:** 19 Aug 2026
- **Also known as:** GHSA-8ff9-hr9f-57m5

## What is CVE-2021-26859?

CVE-2021-26859 is a high-severity vulnerability in Microsoft Power BI Report Server version 15.0.1103.234, published on 11 Mar 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Microsoft Power BI Information Disclosure Vulnerability

## Which versions are affected by CVE-2021-26859?

It affects 1 product.


Products: Microsoft Power Bi Report Server.

## How do I fix CVE-2021-26859?

No fix has been published for CVE-2021-26859 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-26859 being exploited?

There is no known exploitation of CVE-2021-26859 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Power BI Report Server version 15.0.1103.234

- [CVE-2026-65811](https://insights.sbomify.com/CVE-2026-65811/): Power BI Remote Code Execution Vulnerability (high 8.8)
- [CVE-2023-21806](https://insights.sbomify.com/CVE-2023-21806/): Power BI Report Server Spoofing Vulnerability (high 8.2)
- [CVE-2026-58647](https://insights.sbomify.com/CVE-2026-58647/): Microsoft PowerBI Report Server Spoofing Vulnerability (high 8.0)
- [CVE-2026-21229](https://insights.sbomify.com/CVE-2026-21229/): Power BI Remote Code Execution Vulnerability (high 8.0)
- [CVE-2021-41372](https://insights.sbomify.com/CVE-2021-41372/): Power BI Report Server Spoofing Vulnerability (high 7.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-26859 and fix it if it is affected.

What it is: CVE-2021-26859 is a high-severity vulnerability in Microsoft Power BI Report Server version 15.0.1103.234, published on 11 Mar 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-26859 in the wild and no public exploit code.

Affected product: Microsoft Power BI Report Server version 15.0.1103.234. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-26859/ (Markdown: https://insights.sbomify.com/CVE-2021-26859/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-26859
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-26859
- OSV: https://osv.dev/vulnerability/CVE-2021-26859

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-26859/
Summaries are generated and may contain mistakes; the official description above is the record.