CVE-2026-87121 lwIP TCP/IP Stack - Remote Code Execution

lwIP TCP/IP Stack MQTT contains an out-of-bounds write vulnerability in the MQTT component, letting attackers gain full code execution on the device, exploit requires network access.

CVSS base score 9.8 /10
Critical
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.53% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Remote Code Execution
Impact
Remote Code Execution
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
22 September 2026
Updated
15 October 2026
Weakness
CWE-787

Vendor fix

Update to the latest version of lwIP TCP/IP Stack.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

← All CVEs