CVE-2026-77811Network attack vector

Stored XSS via unvalidated integration asset content

Published Aug 21, 2026 · Updated Aug 21, 2026

Stored XSS in OpenSearch Dashboards Observability before 2.19.6 and 3.4 allows remote authenticated users to run JavaScript in other users' sessions. The integrations static file endpoint serves uploaded integration assets containing arbitrary web content without sufficient input validation. Exploitation requires saved-object write permission and another user to open the asset directly, enabling API calls with that user's privileges.

CVSS severity8.7
High
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in OpenSearch Dashboards Observability before 2.19.6 and 3.4 allows remote authenticated users to run JavaScript in other users' sessions. The integrations static file endpoint serves uploaded integration assets containing arbitrary web content without sufficient input validation. Exploitation requires saved-object write permission and another user to open the asset directly, enabling API calls with that user's privileges.

The record

CVE
CVE-2026-77811
Published
Aug 21, 2026
Updated
Aug 21, 2026
Vendor
OpenSearch Software Foundation
Product
OpenSearch Dashboards Observability
Classifications
CWE-79, CAPEC-592, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 21, 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=0 <2.19.6
  2. Affected versionversion=0 <3.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenSearch Software Foundation · OpenSearch Dashboards Observabilityversion=0 <2.19.6; version=0 <3.4

Published CVSS scores

6.2AmazonCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
8.7AmazonCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC-592Stored XSS
T1203Exploitation for Client Execution

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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