CVE-2026-20204
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 · uneditedIn Splunk Enterprise versions below 10.2.1, 10.0.5, 9.4.10, and 9.3.11, and Splunk Cloud Platform versions below 10.4.2603.0, 10.3.2512.5, 10.2.2510.9, 10.1.2507.19, 10.0.2503.13, and 9.3.2411.127, a low-privileged user that does not hold the `admin` or `power` Splunk roles could potentially perform a Remote Code Execution (RCE) by uploading a malicious file to the `$SPLUNK_HOME/var/run/splunk/apptemp` directory due to improper handling and insufficient isolation of temporary files within the `apptemp` directory.
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 confidenceA low-privileged user without admin or power roles can achieve Remote Code Execution by uploading malicious files to the $SPLUNK_HOME/var/run/splunk/apptemp directory. The vulnerability stems from improper handling and insufficient isolation of temporary files within the apptemp directory, allowing file write access to be leveraged for code execution.
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>= 9.3.0, < 9.3.11>= 9.4.0, < 9.4.10>= 10.0.0, < 10.0.5= 10.2.0>= 9.3.2411, < 9.3.2411.127>= 10.0.2503, < 10.0.2503.13>= 10.1.2507, < 10.1.2507.19>= 10.2.2510, < 10.2.2510.9>= 10.3.2512, < 10.3.2512.5CVSS 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
- High
- Privileges
- Low
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
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 checksWork through these to decide whether this CVE applies to you.
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Identify Splunk product type and versionRun 'splunk --version' or check $SPLUNK_HOME/etc/splunk.version for the installed Splunk version and product type (Enterprise or Cloud Platform)Affected if The installed version falls within: Splunk Enterprise >= 9.3.0 and < 9.3.11, or >= 9.4.0 and < 9.4.10, or >= 10.0.0 and < 10.0.5, or = 10.2.0; Splunk Cloud Platform >= 9.3.2411 and < 9.3.2411.127, or >= 10.0.2503 and < 10.0.2503.13, or >= 10.1.2507 and < 10.1.2507.19, or >= 10.2.2510 and < 10.2.2510
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Verify apptemp directory existsCheck if $SPLUNK_HOME/var/run/splunk/apptemp directory exists on the filesystem using 'ls -la $SPLUNK_HOME/var/run/splunk/apptemp' or equivalent file system queryAffected if The apptemp directory exists and is present on the system (this is the directory where the vulnerability can be exploited)
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Check apptemp directory permissionsRun 'ls -ld $SPLUNK_HOME/var/run/splunk/apptemp' or inspect file permissions to determine if low-privileged users have write access to the directoryAffected if The apptemp directory is world-writable or writable by non-admin users (the vulnerability requires write access to this directory for exploitation)
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Audit apptemp directory for suspicious filesList contents of $SPLUNK_HOME/var/run/splunk/apptemp using 'ls -la $SPLUNK_HOME/var/run/splunk/apptemp' and review for unexpected files such as scripts, binaries, or files with unusual extensionsAffected if Unexpected files are present in the apptemp directory, particularly executable scripts, compiled binaries, or files that were not uploaded through legitimate Splunk operations
A system is affected if it runs a vulnerable Splunk version AND the apptemp directory is present with write access available to low-privileged users, allowing potential unauthorized file uploads that could lead to code execution.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped9.3.119.3.2411.1279.4.10
Upgrade Splunk Enterprise to versions 10.2.1, 10.0.5, 9.4.10, or 9.3.11 and above, or upgrade Splunk Cloud Platform to versions 10.4.2603.0, 10.3.2512.5, 10.2.2510.9, 10.1.2507.19, 10.0.2503.13, or 9.3.2411.127 and above.
Splunk Enterprise: upgrade to 9.3.11, 9.4.10, 10.0.5, 10.2.1, or later | Splunk Cloud Platform: upgrade to 9.3.2411.127, 10.0.2503.13, 10.1.2507.19, 10.2.2510.9, or later (or to 10.3.2512.5 / 10.4.2603.0 if available)
- 1. Identify your current Splunk Enterprise or Splunk Cloud Platform version using the Splunk web interface (Settings > About > Version) or by running 'splunk version' from the command line.
- 2. For Splunk Enterprise: Schedule a maintenance window and back up your Splunk configuration directory ($SPLUNK_HOME/etc) and any custom apps.
- 3. Download the appropriate fixed version from splunk.com: 9.3.11, 9.4.10, 10.0.5, or 10.2.1 (or later) from the Splunk download page.
- 4. For Splunk Enterprise on-premises: Stop the Splunk service using './splunk stop', then install the upgrade using the appropriate method for your OS (MSI installer on Windows, tar/rpm/deb package on Linux).
- 5. After upgrade, start Splunk service using './splunk start' and verify the version number matches the expected fixed release.
- 6. For Splunk Cloud Platform: Contact Splunk Support to schedule the upgrade to the appropriate patched version (9.3.2411.127, 10.0.2503.13, 10.1.2507.19, 10.2.2510.9, or later).
- 7. After upgrade, verify the vulnerability is resolved by confirming the $SPLUNK_HOME/var/run/splunk/apptemp directory is properly secured and low-privileged users cannot write arbitrary files there.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20204 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-20204 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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