Troubleshooting Splunk Enterprise RPM Upgrades on Linux

Applicability

Applies to Splunk Enterprise on Linux when an RPM-based installation is being upgraded. A publicly documented /var/tmp execution issue applies to upgrades to Splunk Enterprise 9.4.15, 10.0.10, 10.2.7, and 10.4.3 when /var/tmp is mounted with noexec. The cited support article lists 9.4.17, 10.0.12, 10.2.9, and 10.6.1.x as fixed versions for that issue. Confirm applicability against the target release’s current documentation.CVE-2026-76266 is a separate issue. The Splunk advisory describes its affected and fixed versions and recommends a tar file instead of a Linux package as a mitigation.

Description

An RPM upgrade can fail with a permission error if an installer pre-install step attempts to execute a temporary file from /var/tmp while that directory is mounted with noexec. The exact temporary filename can vary. A permission-denied error followed by an aborted pre-install step is a relevant symptom.

This is distinct from CVE-2026-76266, which concerns Linux package-upgrade maintainer scripts. The Splunk advisory recommends a tar-file upgrade as a mitigation for that vulnerability. The two situations should not be treated as interchangeable: the appropriate upgrade method depends on the target version and the issue being addressed.

Investigation

1. Confirm the installed Splunk Enterprise version, target version, Linux distribution, and installation method.
2. Check whether /var/tmp is mounted with noexec. If an RPM upgrade reports a permission error while executing a temporary pre-install file, compare the error with the symptoms in the linked support article.
3. Determine whether systemd manages the Splunk service. Confirm the service can be stopped cleanly through the configured service manager before starting a package upgrade.
4. Review the target release’s upgrade notes and the Splunk security advisory for affected versions, fixed versions, and any package-format guidance.
5. Confirm that a current backup and a recovery plan are available before proceeding.

 

Resolution

For the /var/tmp permission error, the public support article describes temporarily allowing execution on /var/tmp during the upgrade, then restoring the original mount restriction. It also describes setting TMPDIR to a location where the Splunk service account has execution permission. These changes can affect host security controls; obtain the required security approval, limit any exception to the upgrade window, and restore the original settings afterward.

For CVE-2026-76266, follow the mitigation and version guidance in the Splunk advisory. The advisory recommends using a tar file instead of a Linux package as a mitigation. A tar-file change can affect package-manager records and service registration; confirm the applicable procedure before changing installation methods.

After the upgrade, verify the Splunk version and service status, check for upgrade errors, and confirm that expected service and deployment functions are operating. Follow the version-specific documentation for any required post-upgrade steps.

 

Revision History

Revision	Publish Date	Comments
1.0	30-Oct-2026	Initial Release