CVE-2026-19505: CWE-347 Improper Verification of Cryptographic Signature in RDK RDK-B WebUI
Description
CVE-2026-19505 is a critical vulnerability in the RDK-B WebUI component of the RDK project. It involves improper verification of cryptographic signatures in the file jst_functions.c, allowing remote attackers to bypass authentication. By crafting a forged JWT with an invalid RSA signature, an attacker can gain administrative access to the system.
CVSS v3.1
Score 9.8critical
Affected software
RDK
RDK-B WebUI
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability arises from improper cryptographic signature verification (CWE-347) in the RDK-B WebUI, specifically in the jst_functions.c source file. The flaw allows a remote attacker to bypass authentication controls by submitting a JSON Web Token (JWT) containing an invalid RSA signature, which the system incorrectly accepts as valid. This leads to unauthorized administrative access, compromising confidentiality, integrity, and availability of the affected system.
Potential Impact
Successful exploitation results in full administrative access to the RDK-B WebUI, enabling an attacker to control the system remotely. The CVSS v3.1 base score is 9.8, reflecting a critical severity with network attack vector, no required privileges or user interaction, and high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
No patch or official fix information is currently available. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is released, restrict access to the RDK-B WebUI to trusted networks and monitor for suspicious JWT usage if possible.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- certcc
- Date Reserved
- 2026-08-10T19:13:26.432Z
- State
- PUBLISHED
Threat ID: 6a860605acd9273b49871aa8
Added to database: 08/19/2026, 19:37:41 UTC
Last enriched: 09/11/2026, 06:32:18 UTC
Last updated: 10/04/2026, 10:02:26 UTC
Views: 51
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