VIKTIG INFORMATION om funktionsstörning i Visma PX webb efter Microsoft-uppdatering 9/6

[#1]

Uppdatering 2026-07-15

Nedan uppdatering har Visma fått från Microsoft. Vänligen meddela er IT-avdelning denna information. Vid eventuella frågor kontakta PX Expert via supportportalen.

Microsoft released the following cumulative updates on July 14, 2026 that include the permanent code fix for the issues that previously affected the web application.

 Windows Server 2019: KB5099538 (OS Build 17763.9020)
 Windows Server 2022: KB5099540 (OS Build 20348.5386)

Reset/Remove KIR Policy After Microsoft's New Security Update.

The new update replaces the affected components, so the original problematic behavior is no longer present. Once it is installed, the Known Issue Rollback (KIR) that was previously deployed is no longer needed and should be reset/removed (set to Not Configured).

Recommended Steps

1. Confirm the new cumulative update is installed. Normally applied automatically via WSUS / WUfB, so in most cases this is just a verification check. There is no need to uninstall or reapply the June 9 update.
2. Reset/Remove the KIR policy

Windows Server 2019

1. Open the Group Policy Editor — run gpedit.msc.
2. Navigate to: Computer Configuration Administrative Templates→ → KB5094123 260615_20577 Known Issue Rollback Windows Server→ .
3. Open the setting "KB5094123 260615_20577 Known Issue Rollback" and set it to Not Configured (preferred) or remove the GPO entirely.
4. Click Apply / OK.
5. Open an elevated prompt — right-click Command Prompt or PowerShell Run as administrator→ . (KIR is a Computer Configuration policy, so it requires admin/SYSTEM scope.)
6. Run: gpupdate /force

Windows Server 2022

1. Open the Group Policy Editor — run gpedit.msc.
2. Navigate to: Computer Configuration Administrative Templates→ → KB5094128 260615_20577 Known Issue Rollback Windows Server 2022→ .
3. Open the setting "KB5094128 260615_20577 Known Issue Rollback" and set it to Not Configured (preferred) or remove the GPO entirely.
4. Click Apply / OK.
5. Open an elevated prompt — right-click Command Prompt or PowerShell Run as administrator→.
6. Run: gpupdate /force. Reboot if prompted, to ensure the policy changes are fully applied.

Reboot if prompted, to ensure the policy changes are fully applied.

Reference Links

• Windows Server 2019 — KB5099538 (OS Build 17763.9020):
  https://support.microsoft.com/help/5099538
• Windows Server 2022 — KB5099540 (OS Build 20348.5386): https://support.microsoft.com/en-us/servicing/os/windows-server/2026/07/july-14-2026-kb5099540-os-bu...

Important Note
This cleanup is manual. The KIR is not automatically neutralized simply because the new update is installed. If it is left enabled, it can continue to override the fixed behavior effectively keeping the security mitigation disabled longer than necessary. From a security perspective, the KIR is only a temporary rollback of a specific security change. Once the permanent fix is in place, leaving the KIR active unnecessarily reduces your security posture, so we recommend completing the removal.

Uppdatering 2026-06-29

Nedan uppdatering har Visma fått från Microsoft.  

Vänligen meddela er IT-avdelning denna information.

Vid eventuella frågor kontakta PX Expert via supportportalen. 

The mitigation options provided by Microsoft for the issue introduced by the June 9, 2026 Windows Security Update, that is breaking application functionality. 

Mitigation options:

1. Remove the June 9, 2026 Windows Update

    Pro: Reverts the OS to the previously installed update, providing immediate relief.
  Con: Leaves devices exposed to ALL bug fixes and security protections delivered in the June 9 update.

2. Leave the June 9 update installed AND configure the OS-version-specific KIR to Disabled (Recommended)

   Pro: Devices keep their bug fixes and 199 of 200 security fixes from the update, and affected apps work again.

   Con: Devices lose the single security protection disabled by the KIR until Microsoft's fix is installed in a future update.

Recommended option: Option 2 — applying the Known Issue Rollback (KIR). It restores application functionality while preserving nearly all of the security and bug-fix improvements from the update. A device reboot is required for the KIR to take effect.

KIR MSI download links

- Windows Server 2019 (KB5094123 260615_20577): 

https://download.microsoft.com/download/feba837d-3b58-40f8-8e73-6bfd0105aa29/Windows 10 1809 and Win...

- Windows Server 2022 (KB5094128 260615_20573): 

https://download.microsoft.com/download/611a7394-a91a-4c4e-942e-2263efa27f70/Windows Server 2022 KB5...

Deployment steps

Windows Server 2019 — KB5094123 260615_20577

1. Run the MSI directly on the server
2. Double-click the downloaded .msi, or run it from an elevated command prompt: msiexec /i "Windows Server 2019 KB5094123 260615_20577 Known Issue Rollback.msi"
3. Navigate to the policy setting - Go to: Computer Configuration (run gpedit.msc) → Administrative Templates → KB5094123 260615_20577 Known Issue Rollback → Windows Server 2019. (View attached image)
4. Configure the setting - Open the setting named "KB5094123 260615_20577 Known Issue Rollback" and set it to Disabled. Setting it to Disabled activates the rollback (turns off the problematic code change). Click Apply/OK. (View attached image)
5. Open an elevated prompt — right-click Command Prompt or PowerShell → Run as administrator. (KIR is a Computer Configuration policy, so it needs admin/SYSTEM scope.)
6. Run: gpupdate /force
7. Then to capture the result, run: gpresult /h C:\kir.html
8. Open C:\kir.html in a browser on that server and look for the KB5094123 260615_20577 Known Issue Rollback setting under Applied / winning computer policy, showing Disabled.
9. Reboot the server after confirming it applied — the rollback is only read at boot.

Windows Server 2022 — KB5094128 260615_20573

1. Run the MSI directly on the server
2. Double-click the downloaded .msi, or run it from an elevated command prompt: msiexec /i "Windows Server 2022 KB5094128 260615_20573 Known Issue Rollback.msi"
3. Navigate to the policy setting - Go to: Computer Configuration (run gpedit.msc) → Administrative Templates → KB5094128 260615_20573 Known Issue Rollback → Windows Server 2022. (View attached image)
4. Configure the setting - Open the setting named "KB5094128 260615_20573 Known Issue Rollback" and set it to Disabled. Setting it to Disabled activates the rollback (turns off the problematic code change). Click Apply/OK. (View attached image)
5. Open an elevated prompt — right-click Command Prompt or PowerShell → Run as administrator. (KIR is a Computer Configuration policy, so it needs admin/SYSTEM scope.)
6. Run: gpupdate /force
7. Then to capture the result, run: gpresult /h C:\kir.html
8. Open C:\kir.html in a browser on that server and look for the KB5094128 260615_20573 Known Issue Rollback setting under Applied / winning computer policy, showing Disabled.
9. Reboot the server after confirming it applied — the rollback is only read at boot.

For more information about configuring a Known issue rollback in group policy, please, check  Learn: How to use Group Policy to deploy a Known Issue Rollback 

...................................................................................................................................................................................

Uppdatering 2026-06-16

Nedan uppdatering har Visma fått från Microsoft.

Current Status:

At present: This behavior still wasn't listed as a documented known issue in the official Microsoft update notes for either KB5094123 June 9, 2026—KB5094123 (OS Build 17763.8880) - Microsoft Support or KB5094128. June 9, 2026—KB5094128 (OS Build 20348.5256) - Microsoft Support

Recommendations from Microsoft:
Please, proceed with regression confirmation (rollback ) and due to no official fix, hotfix yet published/released- it is recommended align with internal guidance: delay deployment / consider rollback until Microsoft publishes corrections.

...............................................................................................................................................

2026-06-15

Microsoft publicerade den 9 juni en säkerhetsuppdatering som påverkar hur koden i Visma PX webb fungerar. Detta har medfört att vissa funktioner i systemet för närvarande inte fungerar som förväntat.

Exempel på effekter i systemet

• Attestering av uppdrag kan inte genomföras.
• Klarmarkering på tidrapporter går ej att återställa.

Aktuell status: Vi arbetar fokuserat på frågan och har startat en dialog med Microsoft för att hitta en lösning på problemet.

Åtgärd för IT-avdelningen

För att återställa funktionen i Visma PX webb under tiden utredningen pågår, behöver berörda säkerhetsuppdateringar på webbservern där Visma PX webb är installerat tillfälligt undvikas eller avinstalleras.

• Om uppdateringen inte är installerad: Avvakta med att lägga på säkerhetsuppdateringarna från den 9 juni.
• Om uppdateringen är installerad: Uppdateringen behöver avinstalleras från webbservern för att systemet ska fungera fullt ut.

Följande KB-nummer är påverkade beroende på serverversion:

Serverversion	KB-nummer
Windows Server 2022	KB5094128
Windows Server 2019	KB5094123

Vi uppdaterar er på Visma Community så snart vi har ny information.