Security Advisory 0218 .CSAF
Date: November 10, 2026
| Revision | Date | Changes |
|---|---|---|
| 1.0 | November 10, 2026 | Initial release |
The CVE-ID tracking this issue: CVE-2026-121371
CVSSv3.1 Base Score: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)
CVSSv4.0 Base Score: 8.7 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N)
Common Weakness Enumeration: CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
This vulnerability is being tracked by BUG 2048764(EOS), BUG 2069205(DMF)
Description
On affected EOS versions with the eAPI service enabled, a specially crafted HTTP request can allow an unauthenticated, remote attacker to read arbitrary files, including sensitive credentials from the switch filesystem.
This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.
Vulnerability Assessment
Platform and Software Applicability Note
To determine actual exposure, operators should first check their software versions against the "Affected Software" list below. If your software release is not listed, your deployment is not vulnerable, regardless of the hardware platform in use.
Affected Software
EOS Versions
- 4.36.3M and earlier release in 4.36.x train
- 4.35.7M and earlier release in 4.35.x train
- 4.34.9M and earlier release in 4.34.x train
- 4.33.11M and earlier release in 4.33.x train
- All releases in the 4.32.x train
- All releases in the End of Support software release trains
Impact on DANZ Monitoring Fabric (DMF)
DANZ Monitoring Fabric (DMF) deploys a fixed version of Arista EOS on certain managed fabric switches. If the EOS version bundled with a DMF release falls within the affected version range of this advisory, DMF deployments using EOS-based switch platforms may be impacted.
DMF fabric switches running Switch Light OS are not affected by this vulnerability.
Customers running DMF should run the following command on the controller to identify the EOS version bundled with their deployment.
DMF-CONTROLLER> show version details
...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Platform files ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
File Hcl supported Platform
-------------------------------------------------------------------------------------|-------------|-----------------------------------|
...
EOS-4.36.2F-49446791.volgarel.1-x86_64.swi True x86_64-7289-eos
EOS-4.36.2F-49446791.volgarel.1-x86_64.swi True i686-7289-eos
EOS-4.36.2F-49446791.volgarel.1-x86_64.swi False x86_64-ccs-720df-48y-eos
Affected Platforms
- Arista EOS-based products:
- 710 Series
- 720D Series
- 720XP/722XPM Series
- 750X Series
- 7010TX Series
- 7020R/R4 Series
- 7130 Series running EOS
- 7170 Series
- 7050X3/X4 Series
- 7060X/X2/X4/X5/X6/XE7 Series
- 7260X/X3 Series
- 7280R/R2/R3/R4 Series
- 7300X/X3 Series
- 7320X Series
- 7358X4 Series
- 7368X4 Series
- 7388X5 Series
- 7500R/R2/R3 Series
- 7800R3/R4 Series
- 7700R4 Series
- AWE 5000 Series
- AWE 7200R Series
- ZTX-7200 Series
- CloudEOS
- cEOS-lab
- vEOS-lab
- CloudVision eXchange, virtual or physical appliance
- Wi-Fi Access Points
- CloudVision CUE cloud service delivery
- CloudVision Portal on-premises, virtual appliance or physical appliance (including the CV-CUE on premises software)
- CloudVision Appliance Software
- CloudVision as-a-Service
- CloudVision AGNI - Cloud service delivery
- CloudVision AGNI - Virtual or physical appliance
- Arista Converged Cloud Fabric (formerly Big Switch BCF)
- DANZ Monitoring Fabric (DMF) - Controller Appliance
- DANZ Monitoring Fabric (DMF) - Analytics Node Appliance
- DANZ Monitoring Fabric (DMF) - Recorder Node Appliance
- DANZ Monitoring Fabric (DMF) - Service Node Appliance
- Arista Multi Cloud Director (formerly Big Switch MCD)
- Arista Network Detection and Response (NDR) Security Platform (Formerly Awake NDR)
- Arista Edge Threat Management - Arista NG Firewall and Arista Micro Edge (Formerly Untangle)
- Arista NetVisor OS, Arista NetVisor UNUM, and Insight Analytics (Formerly Pluribus)
- VeloCloud Orchestrator (Formerly VeloCloud Orchestrator by Broadcom)
- VeloCloud Gateway (Formerly VeloCloud Gateway by Broadcom)
- VeloCloud Edge (Formerly VeloCloud Edge by Broadcom)
Required Configuration for Exploitation
- eAPI is enabled and running
- default-service is enabled
Note: The conditions listed above reflect default system configurations. As a result, systems remain vulnerable even without custom or explicit configuration changes.
To check if eAPI service is running, use the following command:
switch>show management api http-commands Enabled: Yes HTTPS server: running, set to use port 443 HTTP server: running, set to use port 80 Local HTTP server: shutdown, no authentication, set to use port 8080 Unix Socket server: shutdown, no authentication VRFs: default Hits: 0 Last hit: never Bytes in: 0 Bytes out: 0 Requests: 0 Commands: 0 Duration: 0.0 seconds SSL Profile: ARISTA_DEFAULT_SELF_SIGNED_PROFILE, valid FIPS Mode: No QoS DSCP: 0 Session Timeout: 1440 minutes Log Level: none CSP Frame Ancestor: None TLS Protocols: 1.0 1.1 1.2 1.3 URLs --------------------------------------------------------- Management1 : https://10.0.0.1:443 Management1 : http://10.0.0.1:80 Management1 : https://[3fff:ffff::1]:443 Management1 : http://[3fff:ffff::1]:80
To Verify if default-service is enabled by examining running-config all:
switch#show running-config all| sect http-server
management http-server
protocol https port 443
protocol http
no protocol http localhost port 8080
no protocol unix-socket
qos dscp 0
no log-level
default-services
no header csp frame-ancestors
no cors allowed-origin
no protocol https ssl profile
switch#show running-config all| sect http-commands
management api http-commands
protocol https port 443
no protocol http port 80
no protocol http localhost port 8080
no protocol unix-socket
qos dscp 0
no log-level
default-services
no header csp frame-ancestors
...
Indicators of Compromise
Review local nginx access logs located at /var/log/nginx-access.log for irregular HTTP requests targeting device static resources, specifically focusing on requests constructed with unexpected paths.
Mitigation
The recommended mitigation is to disable default services on the management HTTP server. Disabling the default services removes access to the built-in eAPI documentation/explorer (the web UI accessible to) and TapAgg GUI.
switch(config)#management http-server switch(config-mgmt-http-server)#no default-services switch#show running-config | sect http-server management http-server protocol http no default-services
switch(config)#management api http-commands
switch(config-mgmt-api-http-cmds)#no default-services
switch#show running-config | sect http-commands
management api http-commands
protocol http
no default-services
no shutdown
Resolution
The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Arista recommends customers move to the latest version of each release that contains all the fixes listed below. For more information about upgrading see EOS User Manual: Upgrades and Downgrades
- 4.37.0F and later release in 4.37.x train
- 4.36.3.2M and later releases in the 4.36.x train
- 4.35.7.2M and later releases in the 4.35.x train
- 4.34.9.2M and later releases in the 4.34.x train
- 4.33.11.2M and later releases in the 4.33.x train
Hotfix
No hotfix available for this issue.
For More Information
If you require further assistance, or if you have any further questions regarding this security notice, please contact the Arista Networks Technical Assistance Center (TAC) by one of the following methods:
- Open a Service Request
- By email: This email address is being protected from spambots. You need JavaScript enabled to view it.
- By telephone: List of regional telephone numbers
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