CVE-2026-73459 — HIGH (7.4)

Vulnerability Description

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 Score

7.4

HIGH

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Attack Vector

ADJACENT_NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

CHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Related Weaknesses (CWE)

CWE-354

References

https://www.arista.com/en/support/advisories-notices/security-advisory/24716-sec

FAQ

What is CVE-2026-73459?

CVE-2026-73459 is a vulnerability with a CVSS score of 7.4 (HIGH). 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...

How severe is CVE-2026-73459?

CVE-2026-73459 has been rated HIGH with a CVSS base score of 7.4/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-73459?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.