AWS Security Bulletins: CVE-2026-18420 - Remote Code Execution via Prototype Pollution in OpenSearch Dashboards TSVB Plugin
AWS Security Bulletins has published a new security advisory. Here is a summary and what to do.
Key points
- New advisory from AWS Security Bulletins.
- Review affected versions in the advisory.
- Apply updates promptly.
AWS Security Bulletins published a security advisory titled “CVE-2026-18420 - Remote Code Execution via Prototype Pollution in OpenSearch Dashboards TSVB Plugin”.
At a glance
- Publisher
- AWS Security Bulletins
- CVEs
- CVE-2026-18420
What the advisory says
Bulletin ID: 2026-085-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 08/20/2026 13:30 PM PDT Description: Improper input validation in the Time Series Visual Builder (TSVB) plugin in OpenSearch Dashboards before 3.8 allows a remote authenticated user with standard data access permissions to execute arbitrary code on the server by sending a crafted JSON payload to the metrics visualization API endpoint. To mitigate this issue, users should upgrade to OpenSearch Dashboards 3.8 or later. Impacted products and versions: - OpenSearch-Dashboards (open-source, self-managed): >=3.0.0, <3.8.0 - OpenSearch-Dashboards (AWS Managed): >=3.0.0, <3.8.0 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.
What should you do?
- Read the full vendor advisory linked below and confirm whether you run affected versions.
- Schedule the recommended update, prioritising internet-facing systems.
- Watch for exploitation reports; unpatched edge devices are frequent targets.
What to do and how to stay safe: CVE-2026-18420
- Vulnerability severity scores ignore your specific architecture and context.
- Exploitability depends on network exposure and user behavior, not just code flaws.
- Prioritization requires continuous asset inventory and threat intelligence alignment.
Risk-based vulnerability management focuses your limited resources on the flaws that actually threaten your business. Start by mapping your critical assets and checking for active exploits to prioritize your backlog.
Step-by-step guide: Risk-Based Vulnerability Management: Prioritize Fixes by Actual Danger
General security guidance from the Threat Times newsroom. It is not confirmed advice from the organisations named in this story.
