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TI-2026-51565 Aliases CVE-2026-73449GHSA-x95c-w9r9-rqxj

Authentication bypass by spoofing in Arista EOS

Priority LOW 26CWE-290Published · Updated

Key facts

Attack vector
Adjacent network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-290.

Summary

On affected platforms running Arista EOS with both 802.1X port authentication and the RADIUS proxy feature configured with dynamic authorization, a low-privileged attacker on an adjacent network segment who induces a RADIUS packet through a configured RADIUS proxy client can prevent RADIUS dynamic authorization messages, including Change-of-Authorization (CoA) and Disconnect-Requests as defined in RFC 5176, from being applied to locally authenticated 802.1X sessions. This allows an endpoint session that a RADIUS server or network access control system has ordered disconnected to remain authorized on the network. Both 802.1X port authentication with dynamic authorization and RADIUS proxy with dynamic authorization must be explicitly configured for a deployment to be exposed to this issue. This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00239 15th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
AristaEOS4.36.0 – 4.36.1F; 4.35.0 – 4.35.5M; 4.34.0 – 4.34.7.1M—No fix listedCNA
  • EOS VendorArista Affected 4.36.0 – 4.36.1F; 4.35.0 – 4.35.5M; 4.34.0 – 4.34.7.1M Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-73449
  2. 2026-10-03 Alias added: GHSA-x95c-w9r9-rqxj

References

Other 1

  • TI-2026-79524 Privilege escalation in Arista VeloCloud Orchestrator on-premises KEVCVSS 4.0CRITICAL 9.4
  • TI-2026-63212 Improper input validation in Arista VeloCloud Orchestrator On-Prem KEVCVSS 4.0CRITICAL 9.5
  • TI-2026-13992 VeloCloud Orchestrator OS Command Injection KEVCVSS 4.0CRITICAL 10.0
  • TI-2014-05975 GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed… KEVCVSS 3.1CRITICAL 9.8
  • TI-2014-05157 GNU Bash through 4.3 processes trailing strings after function definitions in the values… KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-23989 crypto: algif_aead - Revert to operating out-of-place KEVCVSS 3.1HIGH 7.8
See all 216 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences