CVE-2026-19505Network attack vector

Admin access via JWT signature bypass

Published Aug 19, 2026 · Updated Aug 19, 2026

Authentication bypass in RDK Management LLC RDK-B WebUI rdkb-2025q4-kirkstone allows remote attackers to gain admin access via a forged JWT. In javascript-templates/source/jst_functions.c, JWT authentication incorrectly treats OpenSSL EVP_VerifyFinal() returning 0 for an invalid signature as a successful verification result, so tampered RSA-signed tokens are accepted. Any attacker with network access to the WebUI can submit a forged token and log in as the privileged user; the published records describe administrative access, not a broader code-execution outcome for this CVE.

CVSS severityUnavailable
Unscored
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in RDK Management LLC RDK-B WebUI rdkb-2025q4-kirkstone allows remote attackers to gain admin access via a forged JWT. In javascript-templates/source/jst_functions.c, JWT authentication incorrectly treats OpenSSL EVP_VerifyFinal() returning 0 for an invalid signature as a successful verification result, so tampered RSA-signed tokens are accepted. Any attacker with network access to the WebUI can submit a forged token and log in as the privileged user; the published records describe administrative access, not a broader code-execution outcome for this CVE.

The record

CVE
CVE-2026-19505
Published
Aug 19, 2026
Updated
Aug 19, 2026
Vendor
RDK Management LLC
Product
RDK-B WebUI
Classifications
CWE-347, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=rdkb-2025q4-kirkstone

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

RDK Management LLC · RDK-B WebUIversion=rdkb-2025q4-kirkstone

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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