What is CVE-2026-73459?

CVE-2026-73459 is a high-severity vulnerability in Arista Networks Eos, classified under Improper Validation of Integrity Check Value. CVSS score: 7.4/10. Published 2026-09-16.

How severe is CVE-2026-73459?

High severity. CVSS v3 base score is 7.4 out of 10.

Vulnerability in Arista Networks Eos

CVE-2026-73459

On affected platforms running Arista EOS with IS-IS configured, an unauthenticated attacker who can inject a specially crafted IS-IS LSP PDU can cause the legitimate LSP to be unexpectedly purged from the IS-IS link-state database. This may result in traffic loss.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

Affected products

Arista Networks Eos

Weakness classification (CWE)

CWE-354 — Improper Validation of Integrity Check Value

References

psirt@arista.com (vendor-advisory)

Frequently asked questions

What is CVE-2026-73459?: CVE-2026-73459 is a high-severity vulnerability in Arista Networks Eos, classified under Improper Validation of Integrity Check Value. CVSS score: 7.4/10. Published 2026-09-16.
How severe is CVE-2026-73459?: High severity. CVSS v3 base score is 7.4 out of 10.