CVE-2026-4149

Critical

Published: 11 April 2026

Published

11 April 2026

Modified

15 April 2026

KEV Added

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Patch

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CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0105 77.8th percentile

Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-4149 is a critical-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Sonos Era 300 Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 22.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190). What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-10 Information Input Validation good match

prevent

Directly addresses the lack of validation of user-supplied DataOffset in SMB responses, preventing out-of-bounds memory access.

SI-16 Memory Protection good match

prevent

Provides memory safeguards to protect against unauthorized access past the end of allocated buffers triggered by invalid DataOffset values.

SI-2 Flaw Remediation good match

prevent

Mandates identification and correction of the specific SMB buffer validation flaw to eliminate the remote code execution vulnerability.

MITRE ATT&CK Enterprise TechniquesAI

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 →

Why these techniques?

The vulnerability allows remote, unauthenticated attackers to achieve kernel-level RCE by sending crafted SMB responses to the public-facing Sonos Era 300 speaker service.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

NVD Description

Sonos Era 300 SMB Response Out-Of-Bounds Access Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Sonos Era 300. Authentication is not required to exploit this vulnerability. The specific flaw exists within…

the handling of the DataOffset field within SMB responses. The issue results from the lack of proper validation of user-supplied data, which can result in a memory access past the end of an allocated buffer. An attacker can leverage this vulnerability to execute code in the context of the kernel. Was ZDI-CAN-28345.

Deeper analysisAI

CVE-2026-4149 is a remote code execution vulnerability affecting the Sonos Era 300 speaker. The flaw exists in the handling of the DataOffset field within SMB responses, where insufficient validation of user-supplied data allows out-of-bounds memory access past the end of an allocated buffer. Published on 2026-04-11, it carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) and is associated with CWE-119. The issue was originally tracked as ZDI-CAN-28345.

Remote attackers can exploit this vulnerability without authentication over the network. By sending crafted SMB responses to an affected Sonos Era 300 installation, an attacker triggers the out-of-bounds access, enabling arbitrary code execution in the context of the kernel.

The Zero Day Initiative advisory at https://www.zerodayinitiative.com/advisories/ZDI-26-192/ provides further details on the vulnerability. Security practitioners should review this resource for guidance on mitigation measures and any available patches.