Advisory · CVE-2026-76298
Splunk Enterprise PostgreSQL sidecar password can be derived from the cluster ID in search job logs
Splunk Enterprise below 10.4.4 and 10.2.8 derives the PostgreSQL sidecar superuser password from the search head cluster identifier that appears in search job logs, so a user without admin or power roles can derive it and run arbitrary operating system commands as the Splunk user on search head cluster members. CVSS 3.1 8.8.
- Vendor
- Splunk
- Product
- Splunk Enterprise
- Identifier / CWE
- CVE-2026-76298
CWE-321 - Action timing
- Immediate
Explain it like I’m five
The sidecar database password is not really a secret: it is worked out from the cluster name, and that name is printed in logs ordinary users can see, so anyone who can read the logs can work out the master password too.
- 01Low-privilege user reads logs
A user who does not hold the admin or power roles views search job logs that contain the search head cluster identifier.
- 02Password is derived
Per Splunk, the PostgreSQL sidecar service derives its privileged database password from that cluster identifier, so the user can derive the superuser password.
- 03Sidecar access gained
The user authenticates to the PostgreSQL sidecar as its superuser on a search head cluster member.
- 04Operating system commands run
Per Splunk, that access lets the user run arbitrary operating system commands as the user account running Splunk Enterprise on search head cluster members.
What happened
Splunk disclosed CVE-2026-76298 in advisory SVD-2026-1007: in Splunk Enterprise versions below 10.4.4 and 10.2.8, a user who does not hold the admin or power Splunk roles could derive the PostgreSQL sidecar database superuser password and run arbitrary operating system commands as the user account running Splunk Enterprise on search head cluster members. Splunk states the vulnerability is possible because the PostgreSQL sidecar service derives a privileged database password from the search head cluster identifier that appears in search job logs. The weakness is tracked as CWE-321 and the CVSS 3.1 score is 8.8, with network attack vector, low complexity, low privileges required, and no user interaction.
Per Splunk, the fixed releases are 10.4.4 and 10.2.8 or higher for the branch in use; the 10.0 and 9.4 branches are not listed as affected for this CVE in the advisory. If you cannot upgrade immediately, Splunk states you can turn off the PostgreSQL sidecar service by adding a postgres stanza with disabled set to true in server.conf and restarting, but warns not to do this if you use Edge Processor, OpAmp or SPL2 data pipelines on the instance, because turning off PostgreSQL breaks those features.
What to do
- Inventory Splunk Enterprise deployments on the 10.4 and 10.2 branches, especially search head cluster members, and note the version of each.
- Upgrade affected installations to 10.4.4 or 10.2.8 or higher for the branch in use, using the Splunk advisory guidance.
- If an instance cannot be upgraded immediately and does not use Edge Processor, OpAmp or SPL2 pipelines, consider the Splunk workaround of disabling the PostgreSQL sidecar in server.conf and restarting; do not apply it where those features are in use.
- Treat the old derived password as exposed: hunt for unexpected sidecar database connections, superuser sessions and operating system commands spawned by the Splunk account on search head cluster members.
- Review who can read search job logs on affected clusters, and verify the deployed version on every cluster member after updating.
Management note
A derivable database superuser password that ends in operating system command execution is a full search head compromise path from a low-privilege account. Patch search head clusters first, and investigate them as if the password was public, because to any log reader it effectively was.