cPanel update failed, and blocked, due to rpmdb errors

Symptoms

When updates are available for cPanel, but do not install, you may find an error such as this in WHM:

CPANEL_WARN: FATAL Your RPM database appears unstable. It is not possible at the moment to install a simple RPM.

This will also prevent updates with an error similar to the following:

CONFIG_TEXT: [2026-09-04 06:12:18 +0100]  Checking that the RPM DB is OK...
[2026-09-04 06:12:18 +0100]  error: rpmdb: BDB0113 Thread/process 850/139798076880960 failed: BDB1507 Thread died in Berkeley DB library
[2026-09-04 06:12:18 +0100]  error: db5 error(-30973) from dbenv->failchk: BDB0087 DB_RUNRECOVERY: Fatal error, run database recovery
[2026-09-04 06:12:18 +0100]  error: cannot open Packages index using db5 -  (-30973)
[2026-09-04 06:12:18 +0100]  error: cannot open Packages database in /var/lib/rpm
[2026-09-04 06:12:18 +0100]  package glibc is not installed
[2026-09-04 06:12:18 +0100]  FAIL: RPM DB error: error: rpmdb: BDB0113 Thread/process 850/139798076880960 failed: BDB1507 Thread died in Berkeley DB library
[2026-09-04 06:12:18 +0100] error: db5 error(-30973) from dbenv->failchk: BDB0087 DB_RUNRECOVERY: Fatal error, run database recovery
[2026-09-04 06:12:18 +0100] error: cannot open Packages index using db5 -  (-30973)
[2026-09-04 06:12:18 +0100] error: cannot open Packages database in /var/lib/rpm
[2026-09-04 06:12:18 +0100] package glibc is not installed (exit code 1)
[2026-09-04 06:12:18 +0100] E Blocker found: Your RPM database appears unstable. It is not possible at the moment to install a simple RPM.

Cause 

This issue generally indicates an issue with the RPM database not functioning on the server. This is usually due to some form of corruption in the RPM database.

Resolution

Repair the RPM database on the server using the information from the following:

How to repair an RPM database

Note: If this issue is not resolved using the information above, or the database repeatedly becomes corrupted, it will be necessary to work with a qualified system administrator to further review and repair the database.