# CVE-2026-76252: Cross-Site Scripting (XSS) through Splunk Web Message Validation in Splunk Enterprise

> An attacker can execute unauthorized JavaScript in a victim's browser via phishing, potentially accessing data and modifying system integrity in Splunk Enterprise.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 19 Aug 2026
- **Updated:** 26 Aug 2026
- **Also known as:** GHSA-rvpg-4h5m-w25c

## What is CVE-2026-76252?

CVE-2026-76252 is a medium-severity cross-site scripting vulnerability in Splunk Splunk, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

In Splunk Enterprise versions below 10.4.2, 10.2.6, 10.0.9, and 9.4.13, an unauthenticated user who tricks another user into visiting a malicious web page could run unauthorized JavaScript in that user's browser. This could allow for unauthorized access to all relevant data available to that user and actions that affect system integrity. The Cross-Site Scripting (XSS) is possible because Splunk Web does not validate the origin and source of messages received by a page message handler. The vulnerability requires the attacker to phish the affected user by tricking them into initiating a request within their browser. The unauthenticated user should not be able to exploit the vulnerability at will.

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

## Which versions are affected by CVE-2026-76252?

It affects 1 product.


Products: Splunk Splunk.

## How do I fix CVE-2026-76252?

No fix has been published for CVE-2026-76252 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-76252 being exploited?

There is no known exploitation of CVE-2026-76252 in the wild and no public exploit code.

## Other vulnerabilities in Splunk Splunk

- [CVE-2026-20253](https://insights.sbomify.com/CVE-2026-20253/): Splunk Enterprise Missing Authentication for Critical Function (critical 9.8, exploited in the wild)
- [CVE-2026-76268](https://insights.sbomify.com/CVE-2026-76268/): Missing Authentication for Critical Function in the Patroni REST API in Splunk Enterprise (critical 9.8)
- [CVE-2026-76284](https://insights.sbomify.com/CVE-2026-76284/): Improper Neutralization in Splunk Enterprise (critical 9.8)
- [CVE-2026-76285](https://insights.sbomify.com/CVE-2026-76285/): Improper Adherence to Coding Standards in Splunk Enterprise (critical 9.8)
- [CVE-2017-17067](https://insights.sbomify.com/CVE-2017-17067/): Auth bypass in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-76252 and fix it if it is affected.

What it is: CVE-2026-76252 is a medium-severity cross-site scripting vulnerability in Splunk Splunk, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-76252 in the wild and no public exploit code.

Affected product: Splunk Splunk. 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-2026-76252/ (Markdown: https://insights.sbomify.com/CVE-2026-76252/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-76252
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-76252
- OSV: https://osv.dev/vulnerability/CVE-2026-76252

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-76252/
Summaries are generated and may contain mistakes; the official description above is the record.