CVE-2026-77811

Stored Cross-Site Scripting via Integration Template Asset in OpenSearch Dashboards

Published Aug 21, 2026 CVSS 4.0 · 6.2 Medium EPSS < 1% KEV · Not listed
Description
Improper input validation in the dashboards-observability plugin in OpenSearch Dashboards allows a remote authenticated user with write permissions to OpenSearch Dashboards saved objects to execute arbitrary JavaScript in the context of other users' browser sessions by uploading a saved asset with arbitrary web content.

Analysis

AI-generated

Technical impact

The dashboards‑observability plugin for OpenSearch Dashboards stores user‑supplied assets without proper input validation. An authenticated user who has write permissions to saved objects can upload an asset that contains arbitrary JavaScript. When other users load or view the asset, the script runs in their browser context, enabling attackers to steal session data, perform actions on behalf of the user, or lift privileges to other dashboards. The vulnerability is a stored XSS flaw, identified as CWE‑79, and allows the attacker to execute code in the victim’s browser.

Affected Systems

The flaw affects the dashboards‑observability plugin bundled with Amazon OpenSearch Service and the OpenSearch Dashboards dashboards‑observability plugin. Specific versions impacted are not explicitly enumerated in the advisory; however, the references point to versions 2.19.6 and 3.4.0, indicating that the issue may exist in recent releases.

Risk and Exploitability

The CVSS score of 6.2 reflects a moderate impact that requires the attacker to be an authenticated user with write permissions. The EPSS score is unavailable, so the likelihood of exploitation cannot be precisely quantified, and the vulnerability is not listed in the CISA KEV catalog. Attacks would involve creating or uploading a malicious asset as an authorized user and then convincing other users to view or load the asset. Because no server‑side code is executed, the risk is confined to the browser context, yet lateral actions are possible through stolen credentials or session hijacking.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update Amazon OpenSearch Service or OpenSearch Dashboards to the latest version that includes the fix for the dashboards‑observability plugin.
  • Revoke or reduce write permissions to the "saved objects" feature for users who do not need to upload assets.
  • If a patch is not yet available, disable the dashboards‑observability plugin or block the asset upload endpoint to prevent new malicious content from being stored.
  • Implement a review or sanitization policy for any existing uploaded assets to ensure no embedded JavaScript remains on the platform.

Generated by OpenCVE AI on August 21, 2026 at 21:35 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Opensearch opensearch Dashboards
Vendors & Products Opensearch opensearch Dashboards
Type Values Removed Values Added
References
Metrics cvssV4_0

{'score': 6.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:N/SI:H/SA:H'}

cvssV4_0

{'score': 6.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N'}

Type Values Removed Values Added
Description Improper input validation in the dashboards-observability plugin in OpenSearch Dashboards allows a remote authenticated user with write permissions to OpenSearch Dashboards saved objects to execute arbitrary JavaScript in the context of other users' browser sessions by uploading a saved asset with arbitrary web content.
Title Stored Cross-Site Scripting via Integration Template Asset in OpenSearch Dashboards
First Time appeared Aws
Aws amazon Opensearch Service
Opensearch
Opensearch opensearch Dashboards Dashboards-observability Plugin
Weaknesses CWE-79
CPEs cpe:2.3:a:aws:amazon_opensearch_service:*:*:*:*:*:*:*:*
cpe:2.3:a:opensearch:opensearch_dashboards_dashboards-observability_plugin:*:*:*:*:*:*:*:*
Vendors & Products Aws
Aws amazon Opensearch Service
Opensearch
Opensearch opensearch Dashboards Dashboards-observability Plugin
References
Metrics cvssV3_1

{'score': 8.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N'}

cvssV4_0

{'score': 6.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:N/SI:H/SA:H'}

Weaknesses
  • CWE-79

    Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Sources

Status
PUBLISHED
Assigner
AMZN
Published
Updated
Aug 27, 2026, 4:46 PM
Reserved
Aug 21, 2026, 1:59 PM
Status
Awaiting Analysis
Published
Aug 21, 2026, 9:17 PM
Modified
Oct 14, 2026, 7:10 PM