CVE-2026-19505 RDK-B WebUI improper cryptographic signature verification vulnerability
Remote attackers can bypass authentication and gain administrative access by forging JWTs with invalid RSA signatures in RDK-B WebUI.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-19505?
CVE-2026-19505 is a critical authentication bypass vulnerability in RDK-B WebUI, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-347
Which versions are affected by CVE-2026-19505?
How do I fix CVE-2026-19505?
No fix has been published for CVE-2026-19505 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-19505 being exploited?
There is no known exploitation of CVE-2026-19505 in the wild and no public exploit code.
Sources
Also known as GHSA-j328-w5qv-gh82.