CVE-2026-7473

MEDIUM KEV

Arista EOS Unexpected Tunnel Protocol Decapsulation and Forwarding Bypass

Title source: cna
STIX 2.1

Exploitation Summary

CVE-2026-7473 is actively exploited and listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added June 9, 2026. EIP tracks 1 public exploit from researchers including fevar54.

AI-analyzed exploit summary This repository contains a functional exploit for CVE-2026-7473, which allows bypassing tunnel protocol verification in Arista EOS switches. The exploit crafts and sends various tunnel packets (GRE, VXLAN, GUE, IP-in-IP, NVGRE) to demonstrate improper decapsulation and forwarding.

Description

On affected platforms running Arista EOS where a tunnel decapsulation configuration—such as VXLAN (Virtual Extensible LAN), decap-groups, or a GRE (Generic Routing Encapsulation) tunnel interface—is present, the switch will incorrectly decapsulate and forward other unexpected tunneled packet with a destination IP matching its configured decapsulation IP. This occurs because the switch does not verify the tunnel protocol type, potentially leading to the unexpected processing of non-configured tunnel traffic. This issue has been reported as being exploited in the wild.

Exploits (1)

github WORKING POC
by fevar54 · pythonpoc
https://github.com/fevar54/CVE-2026-7473---Arista-EOS-Tunnel-Decapsulation-Bypass

This repository contains a functional exploit for CVE-2026-7473, which allows bypassing tunnel protocol verification in Arista EOS switches. The exploit crafts and sends various tunnel packets (GRE, VXLAN, GUE, IP-in-IP, NVGRE) to demonstrate improper decapsulation and forwarding.

Classification
Working Poc 95%
Attack Type
Other
Complexity
Moderate
Reliability
Reliable
Target: Arista EOS (versions 4.36.x and below)
No auth needed
Prerequisites: Arista EOS switch configured as a tunnel endpoint with a decapsulation IP · Network access to the target switch
devstral-2 · analyzed Jun 10, 2026 Full analysis →

Scores

CVSS v3 5.8
EPSS 0.0038
EPSS Percentile 29.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation active
Automatable yes
Technical Impact total

Details

CISA KEV 2026-06-09
VulnCheck KEV 2026-06-05
ENISA EUVD EUVD-2026-34858
CWE
CWE-1023
Status published
Products (8)
arista/eos
Arista Networks/EOS < 4.30
Arista Networks/EOS 4.31.0 - 4.31
Arista Networks/EOS 4.32.0 - 4.32
Arista Networks/EOS 4.33.0 - 4.33
Arista Networks/EOS 4.34.0 - 4.34
Arista Networks/EOS 4.35.0 - 4.35
Arista Networks/EOS 4.36.0
Published Jun 05, 2026
KEV Added Jun 09, 2026
Tracked Since Jun 05, 2026