CVE-2026-76253: Splunk Enterprise Privilege Escalation Flaw

CVE-2026-76253 Overview

CVE-2026-76253 is a privilege escalation vulnerability in Splunk Enterprise that allows low-privileged users with the schedule_search capability to execute arbitrary Search Processing Language (SPL) commands at the highest system privilege level. The flaw resides in how scheduled search alert action configurations handle user-specific settings before the search scheduler runs alert actions. Attackers can read every credential stored in the credential store, modify data, and undermine system integrity and availability. The vulnerability affects Splunk Enterprise versions below 10.4.2, 10.2.6, 10.0.9, and 9.4.14, and is classified under [CWE-269] Improper Privilege Management.

Critical Impact
Any authenticated user with the schedule_search capability can obtain full system privileges and exfiltrate all stored credentials, resulting in complete compromise of the Splunk deployment.

Affected Products

Splunk Enterprise versions below 10.4.2
Splunk Enterprise versions below 10.2.6 and 10.0.9
Splunk Enterprise versions below 9.4.14

Discovery Timeline

2026-08-19 - CVE-2026-76253 published to NVD
2026-08-20 - Last updated in NVD database

Technical Details for CVE-2026-76253

Vulnerability Analysis

The vulnerability stems from insufficient enforcement of user context in the Splunk scheduler pipeline. Scheduled searches in Splunk can trigger alert actions when search results meet defined criteria. Alert actions execute SPL commands and can interact with the credential store to authenticate against downstream systems. The scheduler runs these alert actions using elevated system privileges rather than the invoking user's privilege level.

Because user-specific alert action settings are not properly restricted before the scheduler executes them, a user holding only the schedule_search capability can craft an alert action configuration that runs arbitrary SPL. The scheduler then executes those commands with system-level authority, bypassing the user's normal role-based restrictions.

Root Cause

The root cause is improper privilege management [CWE-269] in the scheduled search alert action configuration flow. Splunk fails to validate or constrain user-supplied alert action settings against the invoking user's role capabilities before elevating execution to the scheduler's privilege context. This design flaw allows privilege boundaries defined by role capabilities to be circumvented via legitimate configuration paths.

Attack Vector

An authenticated attacker with a role that includes the schedule_search capability creates or modifies a scheduled search with an attached alert action. The attacker configures the alert action to execute arbitrary SPL commands or read the credential store. When the scheduler triggers the alert, Splunk runs the attacker-supplied logic with system-level privilege. The attacker then harvests stored credentials, modifies indexed data, or disrupts service availability. The attack requires network access to the Splunk instance and valid credentials but no user interaction.

The vulnerability is described in prose because no public proof-of-concept code has been released. See the Splunk Security Advisory SVD-2026-0801 for vendor technical details.

Detection Methods for CVE-2026-76253

Indicators of Compromise

Newly created or modified scheduled searches by non-administrative users referencing sensitive alert actions or the credential store.
Unexpected reads against passwords.conf or the Splunk secret store outside of admin-initiated workflows.
Alert action executions that spawn SPL commands normally restricted to administrator roles.
Audit log entries showing schedule_search capability holders invoking privileged SPL such as | rest, | script, or | sendemail with attacker-controlled parameters.

Detection Strategies

Review the Splunk _audit and _internal indexes for scheduled search creation events tied to low-privileged accounts.
Baseline expected alert action usage per role and alert on deviations, particularly around credential-access SPL commands.
Correlate scheduler execution events with the invoking user's role capabilities to detect privilege boundary violations.

Monitoring Recommendations

Enable and forward Splunk audit logs to a centralized SIEM for continuous review.
Monitor changes to savedsearches.conf and alert action stanzas across all app contexts.
Track credential store access events and correlate against known administrative activity windows.

How to Mitigate CVE-2026-76253

Immediate Actions Required

Upgrade Splunk Enterprise to 10.4.2, 10.2.6, 10.0.9, 9.4.14, or later as soon as possible.
Audit all roles that include the schedule_search capability and remove it from users who do not require scheduled search functionality.
Rotate credentials stored in the Splunk credential store if unauthorized scheduled search activity is suspected.
Review recently created or modified scheduled searches and alert actions for unexpected SPL commands.

Patch Information

Splunk has released fixed versions addressing this vulnerability. Upgrade to Splunk Enterprise 10.4.2, 10.2.6, 10.0.9, 9.4.14, or newer. Refer to the Splunk Security Advisory SVD-2026-0801 for complete patch details and version-specific guidance.

Workarounds

Restrict the schedule_search capability to trusted administrative roles only until patching is complete.
Disable scheduled searches for non-administrative user roles as a temporary control.
Enforce configuration file precedence to prevent user-scoped savedsearches.conf from overriding system-level restrictions.
Increase audit log retention and alerting on scheduler activity for high-fidelity detection during the mitigation window.

bash

# Example: list roles that grant the schedule_search capability
$SPLUNK_HOME/bin/splunk btool authorize list --debug | grep -E "^\[role_|schedule_search"

# Example: remove schedule_search from a non-admin role via authorize.conf
# [role_analyst]
# schedule_search = disabled