Advisoriesby IbisArista NetworksCVE-2026-73450
Arista Networks EOS: insufficient authenticity check
No fix yet
On affected platforms running Arista EOS with MLAG Dual Primary Detection configured, an unauthenticated attacker with access to the Dual Primary Detection network segment can send specially crafted packets to interfere with the dual-primary state. If the MLAG primary switch fails while these packets are present, the secondary switch incorrectly concludes it is in a dual-primary condition and err-disables its interfaces, leading to a traffic interruption.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| EOS Product | >= 4.36.0, <= 4.36.1F | No fix yet |
| >= 4.35.0, <= 4.35.5M | No fix yet | |
| >= 4.34.0, <= 4.34.7.1M | No fix yet | |
| >= 4.33.0, <= 4.33.9M | No fix yet |
Details and references
- CVSS 4.0
- CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:H/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
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-345