---
cve: "CVE-2026-48686"
severity: "CRITICAL"
cvss: 9.8
epss: "57%"
vendor: "n/a"
kev: false
exploited: false
published: "2026-05-26 16:16:26"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-12T02:41:30+02:00"
---

# CVE-2026-48686

> 9.8 CRITICAL · 🧪 PoC

## Beschreibung

FastNetMon Community Edition through 1.2.9 contains a stack-based buffer overflow in the BGP NLRI (Network Layer Reachability Information) decoder. The function decode_bgp_subnet_encoding_ipv4_raw() in src/bgp_protocol.cpp reads prefix_bit_length directly from the BGP packet (line 99) without validating it is  32 causes undefined behavior.

## CVSS-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- 394fbe06d112f9609d3d1cb10d60cbf98347c96a (Commit)

## Referenzen

- <https://github.com/pavel-odintsov/fastnetmon>
- <https://github.com/pavel-odintsov/fastnetmon/blob/master/src/bgp_protocol.cpp>
- <https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48686-bgp-nlri-stack-overflow>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-48686) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_