CVE-2026-20202
Improper Input Validation in Splunk Usernames Causes Account Issues
Publication date: 2026-04-15
Last updated on: 2026-04-17
Assigner: Cisco Systems, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| splunk | splunk | From 10.0.0 (inc) to 10.0.5 (exc) |
| splunk | splunk | From 9.3.0 (inc) to 9.3.11 (exc) |
| splunk | splunk | From 9.4.0 (inc) to 9.4.10 (exc) |
| splunk | splunk | From 10.2.0 (inc) to 10.2.2 (exc) |
| splunk | splunk_cloud_platform | From 10.0.2503 (inc) to 10.0.2503.13 (exc) |
| splunk | splunk_cloud_platform | From 10.1.2507 (inc) to 10.1.2507.20 (exc) |
| splunk | splunk_cloud_platform | From 10.2.2510 (inc) to 10.2.2510.10 (exc) |
| splunk | splunk_cloud_platform | From 10.3.2512 (inc) to 10.3.2512.6 (exc) |
| splunk | splunk_cloud_platform | From 9.3.2411 (inc) to 9.3.2411.127 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-176 | The product does not properly handle when an input contains Unicode encoding. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability affects certain versions of Splunk Enterprise and Splunk Cloud Platform where a user with the high-privilege capability `edit_user` can create a username containing a null byte or a non-UTF-8 percent-encoded byte due to improper input validation.
Because of this improper validation, usernames may be inconsistently converted into a proper format for storage, which leads to account management issues such as being unable to edit or delete the affected user accounts.
How can this vulnerability impact me? :
The impact of this vulnerability is that user accounts created with specially crafted usernames may become inconsistent in the system, causing difficulties in managing these accounts.
- Inability to edit affected user accounts.
- Inability to delete affected user accounts.
This can lead to administrative challenges and potential security risks if problematic accounts cannot be properly managed or removed.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
No detection methods or specific commands have been provided for this vulnerability.
What immediate steps should I take to mitigate this vulnerability?
The recommended immediate step to mitigate this vulnerability is to upgrade affected Splunk Enterprise and Splunk Cloud Platform versions to the fixed releases.
- Upgrade Splunk Enterprise to version 10.2.2, 10.0.5, 9.4.10, or 9.3.11 or above.
- Upgrade Splunk Cloud Platform to version 10.4.2603.0 or the respective fixed versions listed.
No other mitigations or workarounds are available.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided information does not specify how this vulnerability directly affects compliance with common standards and regulations such as GDPR or HIPAA.