CVE-2026-76389: Cisco Talos Intelligence SSRF Vulnerability

CVE-2026-76389 Overview

CVE-2026-76389 is a Server-Side Request Forgery (SSRF) vulnerability in Cisco Talos Intelligence for Splunk Enterprise Security Cloud versions below 1.0.3. An authenticated user holding a role with the get_talos_enrichment capability can send a crafted request to the Talos intelligence enrichment REST API endpoint. The endpoint accepts the destination for authenticated Splunk management requests from user-controlled request data. This flaw allows the Splunk instance to make outbound requests to an attacker-controlled server, potentially exposing authentication tokens. Exposed tokens can compromise data confidentiality, integrity, and availability across the Splunk environment.

Critical Impact
Authenticated attackers can force the Splunk instance to leak management tokens to attacker-controlled infrastructure, compromising all relevant data and system integrity.

Affected Products

Cisco Talos Intelligence for Splunk Enterprise Security Cloud versions below 1.0.3
Splunk Enterprise Security deployments using the Talos intelligence enrichment integration
Any Splunk instance with roles granted the get_talos_enrichment capability

Discovery Timeline

2026-08-19 - CVE-2026-76389 published to NVD
2026-08-20 - Last updated in NVD database

Technical Details for CVE-2026-76389

Vulnerability Analysis

The vulnerability is a Server-Side Request Forgery flaw classified under [CWE-918]. The Talos intelligence enrichment REST endpoint in the Cisco Talos Intelligence for Splunk Enterprise Security Cloud app trusts a user-supplied destination parameter when initiating authenticated Splunk management requests. An attacker with a low-privilege role that includes the get_talos_enrichment capability crafts a request pointing the destination at an external server. The Splunk instance then issues an authenticated outbound request to that attacker-controlled host, carrying valid management tokens in the process.

Once those tokens leave the trust boundary, the attacker can replay them against Splunk management APIs. This enables read and write access to data, configuration, and administrative functions on the affected Splunk instance.

Root Cause

The root cause is improper validation of the destination URL for authenticated management requests. The REST endpoint accepts the target from request data without restricting it to trusted Splunk management interfaces. This missing allow-list check permits SSRF and token exfiltration.

Attack Vector

Exploitation requires network access to the Splunk REST API and an authenticated session with the get_talos_enrichment capability. The attacker sends a crafted HTTP request to the Talos enrichment endpoint, substituting the destination field with a URL under their control. No user interaction is required. Refer to the Splunk Security Advisory SVD-2026-0808 for full technical details.

Detection Methods for CVE-2026-76389

Indicators of Compromise

Outbound HTTP or HTTPS requests from the Splunk instance to unfamiliar external hosts originating from the Talos enrichment component.
Requests to the Talos intelligence enrichment REST endpoint containing destination parameters that reference non-Splunk hostnames or IP addresses.
Unexpected use of Splunk management tokens from external source IPs following enrichment API activity.

Detection Strategies

Inspect splunkd_access.log for POST or GET requests to Talos enrichment REST paths that include suspicious destination values.
Correlate outbound network flows from Splunk hosts against an allow-list of expected Talos and Cisco endpoints.
Alert on any Splunk management token usage from IP addresses outside the sanctioned management network.

Monitoring Recommendations

Enable audit logging on all custom REST endpoints exposed by the Talos app and forward logs to a central data lake.
Monitor role assignments that grant the get_talos_enrichment capability and flag additions to privileged roles.
Baseline egress traffic from Splunk search heads and indexers to detect anomalous destinations.

How to Mitigate CVE-2026-76389

Immediate Actions Required

Upgrade Cisco Talos Intelligence for Splunk Enterprise Security Cloud to version 1.0.3 or later.
Audit all roles carrying the get_talos_enrichment capability and remove it from users who do not require enrichment functionality.
Rotate any Splunk management tokens and session keys that could have been exposed through the vulnerable endpoint.

Patch Information

Splunk has released a fixed version of the Talos Intelligence app. Upgrade to version 1.0.3 or later as documented in the Splunk Security Advisory SVD-2026-0808. Review deployment guidance in the Splunk documentation for Deploy Cisco Talos Intelligence for Splunk Enterprise Security.

Workarounds

Restrict the get_talos_enrichment capability to a minimal set of trusted administrative roles until patching is complete.
Apply egress network controls on Splunk instances to permit outbound traffic only to known Cisco Talos endpoints.
Place the Splunk management interface behind network segmentation that blocks arbitrary outbound requests to untrusted destinations.

bash

# Configuration example: restrict egress from Splunk hosts to trusted Talos endpoints
# Example iptables rules (adjust destinations to match your environment)
iptables -A OUTPUT -p tcp -d talos-intelligence.cisco.com --dport 443 -j ACCEPT
iptables -A OUTPUT -p tcp --dport 443 -m owner --uid-owner splunk -j REJECT