CVE-2026-20204 | Improper Handling and Insufficient Isolation of Specific Temporary Files in Splunk Enterprise

In 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.

Published: 2026-04-15 Last update: 2026-04-17 Assigner: [email protected] Source: [email protected]

NVD Status：Analyzed，CVE State: published

View at NVD, CVE.org, EUVD

Conclusion & alert: CVE-2026-20204 is rated Moderate Risk (61.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.28%). Core evidence: EPSS rose +3.10% over the last day, indicating growing attacker interest. Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-20204

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.18%	3.28%	+3.10%
2	2026-04-21	0.13%	0.18%	+0.05%
3	2026-04-16	—	0.13%	—

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20204

CVSS metrics for this CVE.

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.1	3.1	HIGH	`CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.2	5.9	[email protected]

Weakness enumeration for CVE-2026-20204

CWE-377 MITRE ↗

Affected software / configurations for CVE-2026-20204

Vendor	Product	Version	Raw CPE
splunk	splunk	>= 9.3.0, < 9.3.11	cpe:2.3:a:splunk:splunk:::::enterprise:::*
splunk	splunk	>= 9.4.0, < 9.4.10	cpe:2.3:a:splunk:splunk:::::enterprise:::*
splunk	splunk	>= 10.0.0, < 10.0.5	cpe:2.3:a:splunk:splunk:::::enterprise:::*
splunk	splunk	10.2.0	cpe:2.3:a:splunk:splunk:10.2.0::::enterprise:::
splunk	splunk_cloud_platform	>= 9.3.2411, < 9.3.2411.127	cpe:2.3:a:splunk:splunk_cloud_platform::::::::
splunk	splunk_cloud_platform	>= 10.0.2503, < 10.0.2503.13	cpe:2.3:a:splunk:splunk_cloud_platform::::::::
splunk	splunk_cloud_platform	>= 10.1.2507, < 10.1.2507.19	cpe:2.3:a:splunk:splunk_cloud_platform::::::::
splunk	splunk_cloud_platform	>= 10.2.2510, < 10.2.2510.9	cpe:2.3:a:splunk:splunk_cloud_platform::::::::
splunk	splunk_cloud_platform	>= 10.3.2512, < 10.3.2512.5	cpe:2.3:a:splunk:splunk_cloud_platform::::::::

References for CVE-2026-20204

URL	Tags
https://advisory.splunk.com/advisories/SVD-2026-0403	Vendor Advisory

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