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TI-2026-51560 Aliases CVE-2026-73443GHSA-vq3p-3r98-j8w8

Authentication bypass by capture-replay in Arista EOS

Priority LOW 24CWE-294Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-294.

Summary

On affected platforms running Arista EOS with VRRPv2 IP-AH authentication configured, an unauthenticated attacker within the same layer 2 network segment on which VRRP is running can capture a legitimate authenticated VRRP advertisement and replay it indefinitely. Replayed advertisements can be used to advertise stale VRRP state, for example to prevent a backup router from taking over the virtual gateway after the original master has gone down, resulting in a denial of service for hosts using the virtual gateway address.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00273 19th 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 – 4.34.7M; 4.33.0 – 4.33.9M—No fix listedCNA
  • EOS VendorArista Affected 4.36.0 – 4.36.1F; 4.35.0 – 4.35.5M; 4.34.0 – 4.34.7M; 4.33.0 – 4.33.9M Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    Arista Networks EOS — arista.com/en/support/advisories-notices/security-advisory/…

    3 records Highest priority Priority LOW 3 LOW

    Other records, highest priority first

    • TI-2026-51561 On affected platforms running Arista EOS with VRRPv2 IP Authentication Header (IP-AH)…Priority LOW 24
    • TI-2026-51559 Sensitive information in log files in Arista EOSPriority LOW 11
    Show all 3 records → Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-73443
  2. 2026-10-03 Alias added: GHSA-vq3p-3r98-j8w8

References

Advisory 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