Improper cryptographic signature verification in `jst_functions.c` in RDK-B WebUI `rdkb-2025q4...
Summary
Vulnerability reported (CVE-2026-19505). Successful exploitation can lead to full system takeover. Exploitable via jst_functions.c.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-19505 has been found.
Attackers can target a specific entry point like jst_functions.c over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "CVE-2026-19505" on the vendor's site.
CVE-2026-19505 — CWE-347 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: jst_functions.c
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-347) has been reported. Attackers reach the vulnerable code path via jst_functions.c without authentication.
Check the vendor advisory for the affected versions. Attack surface: jst_functions.c.
Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで影響コンポーネントを特定する。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- web cret@cert.org
- web cret@cert.org
- web nvd.nist.gov
- web developer.rdkcentral.com
- web whitehats.pwr.edu.pl
- web github.com