Detections
Analytics
Arista Networks EOS BFD Authentication Out-of-bounds Write DoS (SA0206)
high Nessus Plugin ID 380317
Synopsis
The version of Arista Networks EOS running on the remote device is affected by a denial of service vulnerability.Description
The version of Arista Networks EOS running on the remote device is affected by an out-of-bounds write vulnerability as referenced in security advisory SA0206.- On affected platforms running Arista EOS with Bidirectional Forwarding Detection (BFD) configured to use keyed MD5 or keyed SHA1 authentication, an unauthenticated attacker with network adjacency (direct or multi-hop) to a BFD-enabled interface can send a specially crafted BFD packet resulting in a system reboot. (CVE-2026-121368)
Note that exposure requires BFD session authentication to be configured for either MD5 or SHA1 hashing. Nessus has not checked the BFD authentication configuration and has instead relied only on the application's self-reported version number.
Solution
Upgrade to Arista Networks EOS 4.33.11M / 4.34.9M / 4.35.7M / 4.36.3M / 4.37.0F or later.See Also
Plugin Details
Severity: High
ID: 380317
File Name: arista_eos_sa0206.nasl
Version: 1.1
Type: Combined
Family: Misc.
Published: 11/13/2026
Updated: 11/13/2026
Configuration: Enable paranoid mode
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Low
Score: 3.3
Percentile: 50.44
CVSS v2
Risk Factor: High
Base Score: 7.8
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C
CVSS Score Source: CVE-2026-121368
CVSS v3
Risk Factor: High
Base Score: 8.6
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CVSS v4
Risk Factor: High
Base Score: 8.9
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
Vulnerability Information
CPE: cpe:/o:arista:eos
Required KB Items: Host/Arista-EOS/Version, Settings/ParanoidReport
Patch Publication Date: 11/10/2026
Vulnerability Publication Date: 11/10/2026
Reference Information
CVE: CVE-2026-121368
IAVA: 2026-A-1294