Cyber Resilience

CVE-2026-20202

Splunk Cloud Platform 9.3.2411 – 9.3.2411.127

Published
15 April 2026
Modified
17 April 2026
Patch / advisory
View advisory
CVSS Score v3.1 6.6
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0025 16th percentile
Risk Priority 48 floored blend · peak EPSS

Summary

CVE-2026-20202 is a medium-severity Improper Handling of Unicode Encoding (CWE-176) vulnerability in Splunk Splunk Cloud Platform. Its CVSS base score is 6.6 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Invisible Unicode (T1027.018); ranked at the 16th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
CWE-176

Related Threats

MITRE ATT&CK Enterprise Techniques

T1027.018 Invisible Unicode Stealth
Adversaries may abuse invisible or non-printing Unicode characters to conceal malicious content within files, scripts, or text.
attack.mitre.org →
T1027 Obfuscated Files or Information Stealth
Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit.
attack.mitre.org →
T1132 Data Encoding Command And Control
Adversaries may encode data to make the content of command and control traffic more difficult to detect.
attack.mitre.org →
T1132.002 Non-Standard Encoding Command And Control
Adversaries may encode data with a non-standard data encoding system to make the content of command and control traffic more difficult to detect.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

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CVE-2026-20297Same product: Splunk Splunk

Affected Assets

splunk
splunk
9.3.0 — 9.3.11 · 9.4.0 — 9.4.10 · 10.0.0 — 10.0.5
splunk
splunk cloud platform
9.3.2411 — 9.3.2411.127 · 10.0.2503 — 10.0.2503.13 · 10.1.2507 — 10.1.2507.20

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

Input validation directly requires checking and normalizing encodings so that Unicode is handled consistently before further processing.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require proper Unicode/input validation to prevent this weakness.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect Unicode-handling flaws before deployment.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates input validation and encoding handling that can prevent Unicode mishandling.

A.8.26 Application security requirements partial match
prevents

Application security requirements include proper handling of character encodings and input sanitization.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles require robust input processing to avoid encoding-related vulnerabilities.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly address proper Unicode and character-encoding validation.

References