OPACUserCSS system preference is not applied to the OPAC

Overview

Libraries using KohaSupport’s AMIs may have set custom CSS in the OPACUserCSS system preference to modify the appearance of their OPAC. This custom CSS was not being applied, causing the OPAC to appear without the intended styling changes. This issue affects any library that has configured OPACUserCSS.

Affected Versions

• Koha AMI builds released before 2026-05-28.

Remediation

Option 1: Upgrade to Patched AMI

When a patched AMI is available on AWS Marketplace, launch a new instance from it and migrate your data. See the migration guide for step-by-step instructions.

Option 2: Apply Interim Mitigation

No interim mitigation is available. Upgrade to the patched AMI when released.

Option 3: Contact Support

If you are unsure how to apply the above steps, contact us at [email protected] or use the contact form. We can walk you through the fix remotely.

Timeline

References

• KohaSupport Knowledge Base
• Contact KohaSupport