Vulnerability in Arista Extensible Operating System (CVE-2026-7473, CVSS 5.8, KEV)

Summary

Vulnerability in Arista Extensible Operating System (CVE-2026-7473). Risk of unauthorized operations or information disclosure. Listed in CISA KEV — actively exploited.

Original description

The description as published by the source.

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.

Source: NIST National Vulnerability Database NVD GitHub Advisory CISA KEV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-7473 has been found in Arista Extensible Operating System.
Risk of unauthorized operations or information disclosure. CVSS score: 5.8/10.
Note: CISA has officially confirmed this is actively exploited in the wild. Treat it with elevated urgency.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Arista Extensible Operating System CVE-2026-7473" on the vendor's site.

CVE-2026-7473 (Arista Extensible Operating System) — CWE-1023 / CVSS v3 5.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Listed in CISA KEV — actively exploited, treat as top priority.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (CWE-1023) exists in Arista Extensible Operating System.

📍 Affected scope

Check the vendor advisory for the affected versions of Arista Extensible Operating System.

🔥 Severity

Severity: Medium (CVSS 5.8/10). Risk of unauthorized operations or information disclosure. Listed in CISA KEV — actively exploited in the wild, treat as top priority.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
資産台帳・SBOM・依存マニフェストで Arista Extensible Operating System を使っているサービスとバージョンを洗い出す。
2
Consider incident declaration escalate
```
Notify SOC / on-call
```
CISA KEV登録済 = 実環境で悪用が観測されている。侵入の兆候があればインシデント対応宣言、無くてもパッチ適用までWAF強化を最優先で。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

References

advisory NVD
patch arista.com
web psirt@arista.com
web github.com
web cisa.gov