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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-7473

Arista Extensible Operating System Incomplete Comparison with Missing Factors Vulnerability

KEVMEDIUM 6.9EPSS 1.11%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 23 June 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

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.

CVSS 4.0
6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
1.11% probability · 64th percentile
CISA KEV
Listed 9 June 2026 · due 23 June 2026
Weakness
CWE-1023
Affected
arista/eos
Source
psirt@arista.com

CISA notes

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://www.arista.com/en/support/advisories-notices/security-advisory/24005-security-advisory-0137 ; https://nvd.nist.gov/vuln/detail/CVE-2026-7473

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.