CVE-2026-4149 is a critical out-of-bounds memory access flaw (CVSS 9.8) in how the Sonos Era 300 speaker handles SMB responses. The Zero Day Initiative advisory says the fix is in version 83.1-61240. Update the speaker through the Sonos app and confirm the version.
What's affected
Per ZDI advisory ZDI-26-192, the Sonos Era 300 is affected, and the fix landed in version 83.1-61240. The advisory says remote attackers could execute code in the context of the kernel, and that authentication is not required. The flaw is in the handling of the DataOffset field in SMB responses.
The ZDI page scores it 10.0, while the NVD record shows 9.8.
How to check if you're exposed
In the Sonos app, open the system settings and look at the About My System page, which lists the software version for each speaker. Compare it with 83.1-61240. Sonos speakers usually update automatically, but a speaker that has been offline or on an isolated network might lag behind, so check each one.
Use the Sonos release notes page, which the advisory links, to see the current version.
What to do now
- Update every Era 300 to 83.1-61240 or later and confirm each one.
- Place IoT devices like speakers on a separate network or VLAN from computers and servers.
- If you use SMB music libraries on a network share, keep that server under your control and patched, since the flaw concerns the speaker handling responses from an SMB server.
- Turn on automatic updates if you have them off.
Why it matters
The record lists CWE-119, improper restriction of operations within the bounds of a memory buffer. The advisory says the issue comes from the lack of validation of a field in the response, which leads to access past the end of an allocated buffer.
The practical lesson for connected devices is to treat them like any other computer on the network. They run kernel code, parse network protocols and need updates. The record does not flag this CVE as known exploited, and the ZDI page says the vendor was notified in November 2025 and the advisory was released in coordination in March 2026.
Quick check
Do I need to do anything if my speakers update automatically?
Check that they did. Open the app's system information and confirm the version is 83.1-61240 or later.
Sources
Last reviewed: 19 October 2026.
