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Medium

Stored XSS in Splunk Enterprise and Splunk Cloud Platform classic dashboards

IdentifiersCVE-2026-20258CWE-79· Improper Neutralization of Input…

CVE-2026-20258 is a stored cross-site scripting vulnerability in classic dashboard HTML panels in Splunk Enterprise versions below 10.2.4, 10.0.7, 9.4.12, and 9.3.13, and Splunk Cloud Platform versions below 10.3.2512.11, 10.2.2510.15, 10.1.2507.23, and 9.3.2411.132. A low-privileged user who does not have the admin or power role can store a malicious script in a classic dashboard HTML panel. When another user is induced to load the crafted dashboard or initiate the relevant browser request, the injected JavaScript executes in that victim user's browser within the Splunk web context.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation results in unauthorized JavaScript execution in the victim user's browser. Depending on the victim's privileges and session context, this can enable theft of session data, execution of actions as the victim within Splunk Web, access to sensitive dashboard-visible data, and broader client-side compromise of the victim's authenticated Splunk session.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure by restricting low-privileged users' ability to create or modify classic dashboard HTML panels, limiting access to vulnerable Splunk Web instances, monitoring dashboards for malicious embedded content, and maintaining settings that disable embeddable dashboard HTML content where possible. User awareness against phishing is also relevant because exploitation requires tricking a victim into initiating the request.

Remediation

Patch, then assume compromise.

Upgrade to a fixed release. For Splunk Enterprise, upgrade to 10.2.4 or later, 10.0.7 or later, 9.4.12 or later, or 9.3.13 or later. For Splunk Cloud Platform, upgrade to 10.3.2512.11 or later, 10.2.2510.15 or later, 10.1.2507.23 or later, or 9.3.2411.132 or later.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
SplunkCloud Platformapplication
SplunkEnterpriseapplication
SplunkSplunkapplication
SplunkSplunk Cloud Platformapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

2 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

2 SOURCESView more in app
What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES
MITRE CVE
cve.org · CVE-2026-20258
NVD
nvd.nist.gov/vuln/detail/CVE-2026-20258
MITRE CWE · CWE-79
Improper Neutralization of Input During Web…
Vendor Advisory
advisory.splunk.com/advisories/SVD-2026-0608