Cyber Resilience

CVE-2026-76354

Splunk 9.4.0 – 9.4.14

Published
19 August 2026
Modified
21 August 2026
Patch / advisory
View advisory
CVSS Score v3.1 8.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
EPSS Score 0.0025 16th percentile
Risk Priority 58 floored blend · peak EPSS

Summary

CVE-2026-76354 is a high-severity Improper Neutralization of Null Byte or NUL Character (CWE-158) vulnerability in Splunk Splunk. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); 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 10.4.2, 10.2.6, 10.0.9, and 9.4.14, a user who does not hold the "admin" or "power" Splunk roles could affect system integrity and availability by sending a crafted Representational State Transfer (REST) API request that deletes…

more

or temporarily overwrites files writable by the user account running Splunk Enterprise processes on a non-captain search head cluster member. The vulnerability is possible because Search Head Clustering bundle replication does not validate the name of a replicated bundle file or neutralize NUL bytes before constructing the member bundle path. For more information see About search head clustering (https://help.splunk.com/en/splunk-enterprise/administer/distributed-search/10.4/overview-of-search-head-clustering/about-search-head-clustering), Define roles on the Splunk platform with capabilities (https://help.splunk.com/en/splunk-enterprise/administer/manage-users-and-security/10.4/manage-splunk-platform-users-and-roles/define-roles-on-the-splunk-platform-with-capabilities), and Secure Splunk Enterprise service accounts (https://help.splunk.com/en/splunk-enterprise/administer/manage-users-and-security/9.0/install-splunk-enterprise-securely/secure-splunk-enterprise-service-accounts) in the Splunk documentation.

CWE(s)
CWE-158

Related Threats

MITRE ATT&CK Enterprise Techniques

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.

CVEs Like This One

CVE-2026-76344Same product: Splunk Splunk
CVE-2026-76317Same product: Splunk Splunk
CVE-2026-76331Same product: Splunk Splunk
CVE-2023-22942Same product: Splunk Splunk
CVE-2026-76316Same product: Splunk Splunk
CVE-2026-76254Same product: Splunk Splunk
CVE-2026-76355Same product: Splunk Splunk
CVE-2026-20253Same product: Splunk Splunk
CVE-2024-36984Same product: Splunk Splunk
CVE-2026-76336Same product: Splunk Splunk

Affected Assets

splunk
splunk
9.4.0 — 9.4.14 · 10.0.0 — 10.0.9 · 10.2.0 — 10.2.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.10

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

Input validation directly requires neutralizing or rejecting malformed characters such as NUL before they reach downstream components.

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 input neutralization and validation to prevent null-byte flaws.

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 null-byte flaws but does not itself implement the neutralization.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates input validation and sanitization that directly prevents null-byte injection.

A.8.26 Application security requirements partial match
prevents

Application security requirements include explicit rules for neutralizing dangerous characters such as NUL.

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

Secure architecture principles reduce the likelihood of unsafe data flows but do not prescribe character neutralization.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly require proper neutralization of null bytes and other metacharacters.

References