CVE-2026-76337: Splunk Enterprise Information Disclosure

CVE-2026-76337 Overview

CVE-2026-76337 is a path traversal vulnerability [CWE-22] affecting Splunk Enterprise. An unauthenticated remote attacker can read JavaScript files located outside the Splunk Web static directory. The flaw exists because Splunk Web does not restrict static file requests to the configured static directory.

Splunk addressed the issue in versions 10.4.2, 10.2.6, 10.0.9, and 9.4.14. Earlier releases remain exposed to information disclosure through crafted HTTP requests targeting the Splunk Web static file handler.

Critical Impact
Unauthenticated attackers can retrieve JavaScript files outside the intended static directory, potentially exposing application logic or sensitive client-side resources.

Affected Products

Splunk Enterprise versions below 10.4.2 (10.4.x branch)
Splunk Enterprise versions below 10.2.6 and 10.0.9 (10.x branches)
Splunk Enterprise versions below 9.4.14 (9.4.x branch)

Discovery Timeline

2026-08-19 - CVE-2026-76337 published to NVD
2026-08-20 - Last updated in NVD database
Vendor advisory: Splunk Security Advisory SVD-2026-0801

Technical Details for CVE-2026-76337

Vulnerability Analysis

Splunk Web serves static assets such as JavaScript files from a configured static directory. The static file handler fails to enforce that requested paths remain within this directory boundary. An unauthenticated attacker can craft an HTTP request with directory traversal sequences to reach JavaScript files stored elsewhere on the host.

The vulnerability is limited to JavaScript file reads and does not permit modification or code execution. The scope is confined to file disclosure through the Splunk Web interface. No authentication or user interaction is required to trigger the flaw.

Exposed JavaScript files may contain application logic, internal API references, or configuration details useful for reconnaissance. Attackers can chain this information with other weaknesses in the Splunk deployment.

Root Cause

The root cause is missing input validation in the Splunk Web static file request handler. The handler accepts user-supplied path components without canonicalization or containment checks against the configured static directory. This maps directly to [CWE-22]: Improper Limitation of a Pathname to a Restricted Directory.

Attack Vector

Exploitation occurs over the network against a reachable Splunk Web endpoint. The attacker sends an HTTP request that includes traversal sequences within the static file path parameter. The server resolves the path outside the intended directory and returns the JavaScript file contents to the unauthenticated caller.

Environments that expose Splunk Web to untrusted networks face the highest exposure. The Exploit Prediction Scoring System (EPSS) rates this issue at 0.301% probability, placing it in the 22.7 percentile. See Splunk Security Advisory SVD-2026-0801 for vendor technical details.

Detection Methods for CVE-2026-76337

Indicators of Compromise

HTTP requests to Splunk Web static file endpoints containing ../ or URL-encoded traversal sequences such as %2e%2e%2f
Access log entries showing successful 200 responses for static paths that resolve outside the Splunk Web static directory
Unusual volumes of static JavaScript file requests from a single source IP without preceding authentication events

Detection Strategies

Inspect Splunk Web access logs for requests targeting the static asset route with encoded or literal traversal patterns.
Correlate unauthenticated static file access with subsequent probing or authentication attempts from the same source.
Compare returned file paths against the configured Splunk Web static directory to identify out-of-bounds reads.

Monitoring Recommendations

Enable verbose logging on Splunk Web and forward access logs to a central analytics platform for pattern detection.
Alert on repeated 4xx and 5xx responses that indicate path traversal probing before a successful disclosure.
Monitor egress traffic from Splunk hosts for unexpected transfers to external IP addresses.

How to Mitigate CVE-2026-76337

Immediate Actions Required

Upgrade Splunk Enterprise to version 10.4.2, 10.2.6, 10.0.9, or 9.4.14 or later, depending on your deployment branch.
Restrict network exposure of Splunk Web to trusted management networks and administrative VPNs.
Review Splunk Web access logs for evidence of prior exploitation attempts against static file endpoints.

Patch Information

Splunk released fixed versions 10.4.2, 10.2.6, 10.0.9, and 9.4.14 that enforce static file request containment within the configured directory. Administrators should consult Splunk Security Advisory SVD-2026-0801 for upgrade paths, checksum details, and version-specific release notes.

Workarounds

Place Splunk Web behind a reverse proxy that normalizes URLs and blocks path traversal sequences before requests reach the application.
Apply Web Application Firewall (WAF) rules that reject requests containing ../, ..\, or their URL-encoded variants against the Splunk Web static path.
Disable public access to Splunk Web if immediate patching is not feasible, and require VPN or bastion access for administrators.

bash

# Example reverse proxy rule (nginx) to block traversal patterns on Splunk Web
location /en-US/static/ {
    if ($request_uri ~* "(\.\./|\.\.\\|%2e%2e%2f|%2e%2e/)") {
        return 403;
    }
    proxy_pass http://splunk_web_upstream;
}