Arista NetworksCVE-2026-73450
Arista Networks EOS: insufficient authenticity check
High7.0CVE-2026-73450 · Published Sep 16, 2026 · updated Sep 17, 2026
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
More Arista Networks advisories
All Arista Networks| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Sep 16 | Arista Networks EOS: remote code execution | Critical9.2 | No fix yet |
| Sep 16 | Arista Networks EOS: secrets in logs | Medium6.0 | No fix yet |
| Sep 16 | Arista Networks EOS: out-of-bounds read | High7.1 | No fix yet |
| Sep 16 | Arista Networks EOS: secrets in logs | Low2.1 | No fix yet |
| Sep 16 | Arista Networks EOS: denial of service | Medium5.3 | No fix yet |
| Sep 16 | Arista Networks VeloCloud Edge: missing authentication | High8.7 | 5.2.0.0+3 more |