CVE-2026-77811 - Stored Cross-Site Scripting via Integration Template Asset in OpenSearch Dashboards
Bulletin ID: 2026-088-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 08/21/2026 13:00 PM PDT Description: Amazon OpenSearch Service is a managed service that makes it easy to deploy, operate, and scale OpenSearch clusters. We identified CVE-2026-77811, a stored cross-site scripting issue in the dashboards-observability plugin in OpenSearch Dashboards. Improper input validation in the integrations static file endpoint allows a remote authenticated actor with write permissions to OpenSearch Dashboards saved objects to upload a custom integration containing arbitrary JavaScript. When another user accesses the static file endpoint directly, the script executes in their browser session and can perform actions on their behalf, including making API calls to OpenSearch with their privileges. Affected products & versions: OpenSearch Dashboards dashboards-observability plugin (open-source, self-managed): - Affected: versions before 3.4 and versions before 2.19.6 - Fixed: versions 3.4 and 2.19.6 Amazon OpenSearch Service (AWS Managed): - Affected: versions before 3.3 - Fixed: fixed in all affected versions (via service software update) Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.
CSIRTS triage
- What
- Stored cross-site scripting in the dashboards-observability plugin's integrations static file endpoint due to improper input validation.
- Who is affected
- Authenticated users with write permissions to OpenSearch Dashboards saved objects can inject malicious scripts affecting other users.
- Urgency
- Important — requires authenticated attacker with write access; can perform actions with victim's privileges.
- Action
- Upgrade OpenSearch Dashboards to patched version when available.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://aws.amazon.com/security/security-bulletins/rss/2026-088-aws/
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-778110.37% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 30% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-77811 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
Recent advisories for - Stored Cross-Site
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
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- unknownCVE-2026-81907: Concrete CMS 9.5.2 and below is vulnerable to Cross-Site Request Forgery (CSRF) in the Express…nvd · 2026-09-11
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- unknownCVE-2026-79035: A reflected cross-site scripting (XSS) vulnerability in the p.rfihub.com component of Zeta Mar…nvd · 2026-09-11
- mediumCVE-2026-77490: Improper neutralization of input during web page generation ('cross-site scripting') in Micros…nvd · 2026-09-11
- mediumCVE-2026-7298: Improper neutralization of input during web page generation ('cross-site scripting') vulnerabil…nvd · 2026-09-11
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