Secure Boot Violation August 2026

[oscarstandar]

Hi, 
I'm having issues with Secure Boot Violation on one of many HP Pro Mini 260 G9. It seems like the new Microsoft Secure Boot Certificates didn't apply on this one. This is just my guess. We have an IT-partner that made sure we've got all signatures updated. On boot a message appears "Secure Boot Violation - Invalid Signature detected". I have no option to boot into BIOS. I tried to repair / perform an BIOS upgrade with USB (Version 02.24.00 Rev.A). Repair says success but while booting again the computer still get stuck on Secure Boot Violation. According to research and IT-partner they have not seen this kind of problem but know there is a known issue with BIOS version 01.04.05 Rev A. 

How do we get past this problem and get the new signatures for Secure Boot? 

Thanks for any help provided. 

[VikramTheGreat]

Hi @oscarstandar,

Welcome to the HP Support Community.
 

Thank you for the detailed information. I understand that you have several HP Pro Mini 260 G9 systems, but this particular unit is the one that is stopping at “Secure Boot Violation – Invalid Signature detected.” You have also already attempted BIOS recovery using 02.24.00 Rev.A, and the recovery reports success, but the system still does not boot or provide access to BIOS.

I reviewed the information carefully, and there is an important point regarding the new Microsoft Secure Boot certificates.

The HP Pro Mini 260 G9 is not included in HP's published list of supported platforms for the new Secure Boot certificate transition. Because this model is not listed, HP does not provide a supported certificate-update procedure for this platform through that program. Therefore, it would not be appropriate to tell you to install another BIOS or SoftPaq to obtain the new certificates when no applicable package is currently available for this model on the HP Software and Drivers portal.

This also explains why you are unable to find a newer BIOS package for the Pro Mini 260 G9 that addresses the certificate transition. The 02.24.00 Rev.A file you used should not be assumed to contain the new Microsoft Secure Boot certificates simply because the BIOS recovery completed successfully.

Could you please confirm where the 02.24.00 Rev.A BIOS file used on the USB drive came from? In particular, was it a BIOS package that your IT partner had previously downloaded/stored from an earlier installation, rather than a package currently available from the HP Support portal?

I would not recommend attempting to flash a BIOS from another HP platform or manually modifying the Secure Boot databases. That could leave the system in an unsupported firmware state.

Why the Secure Boot Violation can occur
The HP article you referenced explains a known scenario in which certain HP commercial systems can display “Secure Boot Violation – Invalid Signature detected” after a Microsoft cumulative Windows update because the boot component's signature is no longer accepted by the Secure Boot configuration. The article applies to specific HP commercial platforms with Sure Start; it should not be interpreted as confirmation that the Pro Mini 260 G9 is supported by HP's new Secure Boot certificate deployment. HP Commercial Products - Commercial Products (2017-2023) with Sure Start May Experience a Secure Boo...

Since this particular platform is not included in HP's new Secure Boot certificate-supported platform list, and there is no current BIOS package on the HP portal that provides that certificate update for this model, the Secure Boot error cannot be resolved by simply installing a newer certificate package from HP.

At this point, I recommend contacting HP Support with the exact product number B85LCAV, serial number, current BIOS version, and the exact “Secure Boot Violation – Invalid Signature detected” message. HP Support can confirm the platform's support status and advise what options are available for a system that can no longer pass Secure Boot validation.

Please also provide the source of the 02.24.00 Rev.A BIOS file you used. That information is particularly important because you have already confirmed that the BIOS recovery completed successfully, yet the Secure Boot violation remains.

Take care and have an amazing day!