Cross-Site Scripting (XSS) through Splunk Web Message Validation in Splunk Enterprise (CVE-2026-76252) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-76252

Cross-Site Scripting (XSS) through Splunk Web Message Validation in Splunk Enterprise

Answer in brief

CVE-2026-76252 records a Unknown severity vulnerability in Cross-Site Scripting (XSS) through Splunk Web Message Validation in Splunk Enterprise. The current sources do not mark it as known exploited. The current feed maps Splunk/Splunk Enterprise (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 19, 2026Updated Aug 19, 2026Source checked Aug 19, 2026First seen by HOL Aug 19, 2026Material review Aug 19, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Splunk/Splunk Enterprise (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Splunk/Splunk Enterprisegeneric	>=10.4 <10.4.2 \|\| >=10.2 <10.2.6 \|\| >=10.0 <10.0.9 \|\| >=9.4 <9.4.13	10.4.2, 10.2.6, 10.0.9, 9.4.13

Recommended response

Check inventory. Check lockfiles and deployed manifests for Splunk/Splunk Enterprise.
Review the reported fix. Update Splunk/Splunk Enterprise to 10.4.2 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 19, 2026

Sources and claim methodology

Source referenceadvisory.splunk.com

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.