# CVE-2026-21529: Azure HDInsight Spoofing Vulnerability

> An authorized attacker can perform spoofing via cross-site scripting in Azure HDInsight, requiring a patch to mitigate.

- **Severity:** Medium 5.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H/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:** A user has to click or open something
- **Fix available:** No
- **Published:** 10 Feb 2026
- **Updated:** 19 Aug 2026
- **Also known as:** GHSA-8754-7pfj-x7mr

## What is CVE-2026-21529?

CVE-2026-21529 is a medium-severity cross-site scripting vulnerability in Microsoft Azure HDInsight, published on 10 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Improper neutralization of input during web page generation ('cross-site scripting') in Azure HDInsights allows an authorized attacker to perform spoofing over a network.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-21529?

It affects 1 product.


Products: Microsoft Azure Hdinsight.

## How do I fix CVE-2026-21529?

No fix has been published for CVE-2026-21529 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-21529 being exploited?

There is no known exploitation of CVE-2026-21529 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Azure HDInsight

- [CVE-2023-36419](https://insights.sbomify.com/CVE-2023-36419/): Azure HDInsight Apache Oozie Workflow Scheduler XXE Elevation of Privilege Vulnerability (high 8.8)
- [CVE-2026-81349](https://insights.sbomify.com/CVE-2026-81349/): Azure HDInsight Ambari Elevation of Privilege Vulnerability (high 7.2)
- [CVE-2023-38156](https://insights.sbomify.com/CVE-2023-38156/): Azure HDInsight Apache Ambari JDBC Injection Elevation of Privilege Vulnerability (high 7.2)
- [CVE-2023-35394](https://insights.sbomify.com/CVE-2023-35394/): Azure HDInsight Jupyter Notebook Spoofing Vulnerability (medium 4.6)
- [CVE-2023-35393](https://insights.sbomify.com/CVE-2023-35393/): Azure Apache Hive Spoofing Vulnerability (medium 4.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-21529 and fix it if it is affected.

What it is: CVE-2026-21529 is a medium-severity cross-site scripting vulnerability in Microsoft Azure HDInsight, published on 10 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-21529 in the wild and no public exploit code.

Affected product: Microsoft Azure HDInsight. 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-2026-21529/ (Markdown: https://insights.sbomify.com/CVE-2026-21529/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-21529
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21529
- OSV: https://osv.dev/vulnerability/CVE-2026-21529

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-21529/
Summaries are generated and may contain mistakes; the official description above is the record.