CVE-2026-20257Network attack vector

Sensitive-data exfiltration via unchecked dashboard styles

Published Jun 10, 2026 · Updated Jun 10, 2026

Improper input validation in Splunk classic dashboards allows remote authenticated users to exfiltrate browser data through CSS. Classic dashboard panels accept crafted style values that cause browser requests to bypass the Trusted Domains List and reach external domains. A low-privileged user must create the dashboard and induce a higher-privileged user to view it; exposure is limited to data accessible in that viewer's browser.

CVSS severity5.7
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Improper input validation in Splunk classic dashboards allows remote authenticated users to exfiltrate browser data through CSS. Classic dashboard panels accept crafted style values that cause browser requests to bypass the Trusted Domains List and reach external domains. A low-privileged user must create the dashboard and induce a higher-privileged user to view it; exposure is limited to data accessible in that viewer's browser.

The record

CVE
CVE-2026-20257
Published
Jun 10, 2026
Updated
Jun 10, 2026
Vendor
Zoom Video Communications, Inc.
Product
Splunk Enterprise
Classifications
CWE-20
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 10, 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=10.0 <10.0.7
  2. Affected versionversion=10.2 <10.2.4
  3. Affected versionversion=9.3 <9.3.13
  4. Affected versionversion=9.4 <9.4.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Zoom Video Communications, Inc. · Splunk Enterpriseversion=10.0 <10.0.7; version=10.2 <10.2.4; version=9.3 <9.3.13; version=9.4 <9.4.12
Zoom Video Communications, Inc. · Splunk Cloud Platformversion=10.1.2507 <10.1.2507.23; version=10.2.2510 <10.2.2510.15; version=10.3.2512 <10.3.2512.13; version=9.3.2411 <9.3.2411.132

Published CVSS scores

5.7Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation

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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