cbcvebase.
CVE-2026-7473
published 2026-06-05

CVE-2026-7473: On affected platforms running Arista EOS where a tunnel decapsulation configuration—such as VXLAN (Virtual Extensible LAN), decap-groups, or a GRE (Generic…

PriorityP181medium5.8CVSS 3.1
AVNACLPRNUINSCCNILAN
KEVITW
CISA Known Exploited Vulnerabilitydue 2026-06-23
Exploited in the wild
EPSS
27.22%
96.5th percentile
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.

Affected

7 ranges
VendorProductVersion rangeFixed in
arista_networkseos
arista_networkseos* – 4.30
arista_networkseos4.31.0 – 4.31
arista_networkseos4.32.0 – 4.32
arista_networkseos4.33.0 – 4.33
arista_networkseos4.34.0 – 4.34
arista_networkseos4.35.0 – 4.35

Detection & IOCsextracted from sources · hover to see the quote

  • Detect unexpected tunnel protocol decapsulation on Arista EOS devices configured as tunnel endpoints (VXLAN VTEP, GRE tunnel endpoint, or IP decap-group); traffic with a destination IP matching the device's configured decapsulation IP but using a non-configured tunnel protocol type should be flagged as suspicious.
  • Apply ACLs on upstream devices or on the affected Arista EOS devices to selectively allow only legitimate tunnel traffic or block malicious tunnel traffic as a detection/blocking boundary; anomalous tunnel protocol types arriving at decapsulation IPs are the key signal.
  • Focus detection on Arista 7020R, 7280R/R2, and 7500R/R2 series platforms; exploitation requires the device to be configured as a tunnel endpoint with a decapsulation IP.
  • ·No patches are planned by Arista for CVE-2026-7473; the vendor cites risk of breaking existing configurations. Mitigation via ACLs is the recommended approach.
  • ·Exploitation only occurs when the Arista EOS device is actively configured as a tunnel endpoint (VXLAN VTEP, GRE tunnel endpoint, or IP decap-group); devices without such configuration are not affected.
  • ·FCEB agencies are required to apply mitigations by June 23, 2026 per CISA KEV catalog directive BOD 22-01.
  • ·The root cause is the switch not verifying the tunnel protocol type during decapsulation, meaning any tunneled packet destined for the decapsulation IP may be processed regardless of protocol.
  • ·Vendor advisory and additional technical details are available at the Arista security advisory page referenced in the CISA KEV catalog notes.

CVSS provenance

nvdv3.15.8MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
nvdv4.06.9MEDIUMCVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vulncheck6.9MEDIUM
cisa5.8MEDIUM