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.
- 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
- None listed
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
Which versions are affected by CVE-2026-76252?
It affects 1 product.
Products include 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.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
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 Splunk Enterprise Missing Authentication for Critical Function
- CVE-2026-76268 Missing Authentication for Critical Function in the Patroni REST API in Splunk Enterprise
- CVE-2026-76284 Improper Neutralization in Splunk Enterprise
- CVE-2026-76285 Improper Adherence to Coding Standards in Splunk Enterprise
- CVE-2017-17067 Auth bypass in n/a
Sources
Also known as GHSA-rvpg-4h5m-w25c.