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SplunkApplication

CVE-2026-20239

MEDIUM · 6.5 CVSS v3.1 Published 2026-05-20
Fix available
A fix is available. Upgrade to 10.0.5 / 10.0.2503.13 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In Splunk Enterprise versions below 10.2.2 and 10.0.5, and Splunk Cloud Platform versions below 10.3.2512.8, 10.2.2510.11, 10.1.2507.21, and 10.0.2503.13, a user with a role that has access to the `_internal` index could view session cookies and response bodies that contain sensitive data.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In affected Splunk Enterprise and Cloud Platform versions, users with roles that have access to the `_internal` index can view session cookies and HTTP response bodies that contain sensitive data, due to insufficient filtering of internal logs.

MitigationRestrict or revoke user role access to the `_internal` index for users who do not require it, or upgrade to the patched versions (10.2.2, 10.0.5 for Enterprise; 10.3.2512.8, 10.2.2510.11, 10.1.2507.21, 10.0.2503.13 for Cloud).

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
SplunkApplication
Affected:>= 10.0.0, < 10.0.5>= 10.2.0, < 10.2.2
Splunk Cloud PlatformApplication
Affected:>= 10.0.2503, < 10.0.2503.13>= 10.1.2507, < 10.1.2507.21>= 10.2.2510, < 10.2.2510.11>= 10.3.2512, < 10.3.2512.8

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Splunk Enterprise version
    Run `splunk version` from the Splunk bin directory, or view the version in the web UI under Settings > About > Version
    Affected if Version is 10.0.0 through 10.0.4, or 10.2.0 through 10.2.1
  2. Check Splunk Cloud Platform version
    View the version in the Splunk Cloud portal under Settings > About, or contact Splunk Cloud support for version confirmation
    Affected if Version is 10.0.2503 through 10.0.2503.12, 10.1.2507 through 10.1.2507.20, 10.2.2510 through 10.2.2510.10, or 10.3.2512 through 10.3.2512.7
  3. Identify users with access to the _internal index
    In Splunk web UI, go to Settings > Roles and review each role's "Indexes allowed" setting. Check if any non-admin roles include _internal in their allowed indexes
    Affected if Any role other than admin or power user has _internal index access, or if all users can search the _internal index
  4. Verify sensitive data exposure in _internal index
    Run a search as a non-admin user: `index=_internal | search cookie OR session OR Set-Cookie | head 20`. Also try: `index=_internal uri=*cookie* OR uri=*session*`
    Affected if Search results return actual session cookies, authentication tokens, or HTTP response bodies containing sensitive data visible to non-admin users

You are affected if your Splunk version falls within the affected ranges AND non-administrative users have access to the _internal index and can view sensitive session or authentication data in search results.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 10.0.5 / 10.0.2503.13 / 10.1.2507.21 or later
Fixed in 10.0.510.0.2503.1310.1.2507.21
Interim mitigation

Restrict or revoke user role access to the `_internal` index for users who do not require it, or upgrade to the patched versions (10.2.2, 10.0.5 for Enterprise; 10.3.2512.8, 10.2.2510.11, 10.1.2507.21, 10.0.2503.13 for Cloud).

Recommended fix High confidence

Splunk Enterprise: 10.0.5 or 10.2.2 | Splunk Cloud Platform: 10.0.2503.13, 10.1.2507.21, 10.2.2510.11, or 10.3.2512.8

  1. 1. Identify which Splunk product you are running (Splunk Enterprise or Splunk Cloud Platform)
  2. 2. Check your current Splunk version to confirm it falls within the affected range
  3. 3. For Splunk Enterprise: If running 10.0.x, upgrade to 10.0.5. If running 10.2.x, upgrade to 10.2.2
  4. 4. For Splunk Cloud Platform: Upgrade to the version corresponding to your current release: 10.0.2503.13, 10.1.2507.21, 10.2.2510.11, or 10.3.2512.8
  5. 5. After upgrade, verify that users with `_internal` index access can no longer view session cookies and sensitive data in response bodies
  6. 6. ReviewSplunk documentation for any additional post-upgrade configuration steps
Caveat Standard Splunk upgrade considerations apply; test in non-production environment first

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Splunk Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-20239 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data