---
cve: "CVE-2026-87121"
severity: "CRITICAL"
cvss: 9.3
epss: "0.8%"
vendor: "lwIP"
kev: false
exploited: false
published: "2026-09-22 20:17:09"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-27T04:01:34+02:00"
---

# CVE-2026-87121

> 9.3 CRITICAL · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Referenzen

- <https://savannah.nongnu.org/projects/lwip>
- <https://www.cisa.gov/news-events/ics-advisories/icsa-26-265-01>
- <https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-265-01.json>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-87121) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_