Update affected firmware to WTV676-HB6035 Web Interface V3.94 or later, or WTV776-HB6035 Web Interface V4.17 or later. Minimize network exposure by ensuring affected devices are not accessible from the internet. Locate control system networks behind firewalls and isolate from business networks. Use VPNs for remote access and keep VPNs and connected devices updated.
Quick answers
What is CVE-2026-89207?
Update affected firmware to WTV676-HB6035 Web Interface V3.94 or later, or WTV776-HB6035 Web Interface V4.17 or later. Minimize network exposure by ensuring affected devices are not accessible from the internet. Locate control system networks behind firewalls and isolate from business networks. Use VPNs for remote access and keep VPNs and connected devices updated.
How severe is CVE-2026-89207?
medium, CVSS 6.5
Is CVE-2026-89207 known to be exploited?
It is not marked known-exploited in this record.
How should CVE-2026-89207 be mitigated?
Update affected firmware to WTV676-HB6035 Web Interface V3.94 or later, or WTV776-HB6035 Web Interface V4.17 or later. Minimize network exposure by ensuring affected devices are not accessible from the internet. Locate control system networks behind firewalls and isolate from business networks. Use VPNs for remote access and keep VPNs and connected devices updated.
CVSS
6.5
Vendor
Siemens
Published
Sep 30, 2026 · 08:05
Patch
Unknown / not confirmed
Affected products
Siemens WTV676-HB6035, Siemens WTV776-HB6035
Mitigation
Update affected firmware to WTV676-HB6035 Web Interface V3.94 or later, or WTV776-HB6035 Web Interface V4.17 or later. Minimize network exposure by ensuring affected devices are not accessible from the internet. Locate control system networks behind firewalls and isolate from business networks. Use VPNs for remote access and keep VPNs and connected devices updated.
Siemens has disclosed a denial of service vulnerability affecting the web interface firmware of WTV676 and WTV776 ISG devices. The flaw, tracked as CVE-2026-89207, stems from improper validation of specified type of input. An unauthenticated remote attacker could exploit this to force affected devices into protection mode, thereby disabling remote connectivity functions including Web Access. The vulnerability has a CVSS 3.1 base score of 6.5 (Medium). Siemens has released updated firmware versions and recommends immediate updating as the primary mitigation.