CVE-2026-19505

Description

Improper cryptographic signature verification in `jst_functions.c` in RDK-B WebUI `rdkb-2025q4-kirkstone.04.10.26` allows a remote attacker to bypass authentication and obtain administrative access via a forged JWT containing an invalid RSA signature.

References

• https://developer.rdkcentral.com/documentation/documentation/rdk_broadband_documentation/components/webui/
• https://whitehats.pwr.edu.pl//blog/2026-08-19-multiple-vulnerabilities-in-rdkb/