CVE-2026-73443 json
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 indef
published 2026-09-16 53 d ago modified 2026-09-17 52 d ago also EUVD-2026-80996
- cvss
- 4.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 19%
- public exploits
- 0
- none known
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.
Patch / fix
- Arista Networks EOS 4.33.10M, 4.34.8M, 4.35.6M, 4.36.2F
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 52 d ago
Exploit prediction
0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.7 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L |
| CNA | 4.0 | 5.3 | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| CNA | 4.0 | 5.3 | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/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 |
Affected products
- Arista Networks EOS
Classification
- Weakness
-
- CWE-294 Authentication Bypass by Capture-replay
References
Sources
- CVE List CVE-2026-73443
- NVD CVE-2026-73443
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.