Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

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CVE-2026-6272

Severity CVSS v4.0:
HIGH
Type:
CWE-306 Missing Authentication for Critical Function
Publication date:
24/04/2026
Last modified:
24/04/2026

Description

A client holding only a read JWT scope can still register itself as a signal provider through the production kuksa.val.v2 OpenProviderStream API by sending ProvideSignalRequest.<br /> <br /> 1. Obtain any valid token with only read scope.<br /> 2. Connect to the normal production gRPC API (kuksa.val.v2).<br /> 3. Open OpenProviderStream.<br /> 4. Send ProvideSignalRequest for a target signal ID.<br /> 5. Wait for the broker to forward GetProviderValueRequest.<br /> 6. Reply with attacker-controlled GetProviderValueResponse.<br /> 7. Other clients performing GetValue / GetValues for that signal receive forged data.

Impact

Vector 4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H CVSS v4.0 Severity and Metrics:

Base Score: 8.50 HIGH
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): Low
User Interaction (UI): None
Confidentiality (VC): None
Integrity (VI): High
Availability (VA): High
Confidentiality (SC): None
Integrity (SI): High
Availability (SA): High

Base Score 4.0
8.50
Severity 4.0
HIGH

References to Advisories, Solutions, and Tools