CVE-2026-27867 PUBLISHED

An attacker with access via network to the Regesta Smart HD-PLC of the provider Teldat (in this case, registration action is required) who has the vulnerable firmware version could inject a specific payload via the parameter "cmdcookie" withing the /upgrade/index.html resulting in to a Cross-Site Scripting (XSS). This issue affects Regesta Smart HD-PLC - TLDPH16D2:  11.02.06.00.02

The provider has implemented the new version 11.02.06.00.03 which solves the security problems detected in the affected version. The end user has to download the new version in the Teldat - Client Support Portal and implement it in the device ( https://support.teldat.com/portal/supportcontent?page=cgs-customer-global-support&none=true&language=en-US ).

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• https://www.hackrtu.com/blog/CNA-HRTU-0004/
• https://www.hackrtu.com/blog/CNA-CVE-2026-27867/
• https://www.teldat.com/es/
• https://support.teldat.com/images/content/docs/Teldat_dm1087_regesta_smart_nessum_series_installation(1).pdf
• https://support.teldat.com/portal/supportcontent?page=cgs-customer-global-support&none=true&language=en-US

• CWE-79 Improper neutralization of input during web page generation ('cross-site scripting') CWE

• CAPEC-242 Code Injection
• CAPEC-63 Cross-Site Scripting (XSS)