CVE-2026-87121
Critical
Description
lwIP TCP/IP Stack MQTT is vulnerable to an out-of-bounds write, which may allow an attacker to gain full code execution on the device.
SeverityCritical
CVSS9.8
Exploit probability—
ProductTCP/IP Stack MQTT
PublishedSep 22, 2026
First seenSep 22, 2026
Weakness typeCWE-787Out-of-bounds write
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| lwIP TCP/IP Stack MQTT | 2.0.1 ≤ v ≤ 2.2.1 | — |
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