CVE-2026-73459 Arista EOS - Denial of Service

Arista EOS with IS-IS configured contains a denial of service caused by injection of specially crafted IS-IS LSP PDU, letting unauthenticated attackers cause legitimate LSP purging and traffic loss, exploit requires ability to inject IS-IS LSP PDU.

CVSS base score 7.4 /10
High
CISA KEV
Not listed
Public exploit
None known
EPSS
0.17% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Denial of Service
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Published
16 September 2026
Updated
15 October 2026
Weakness
CWE-354

Vendor fix

Update to the latest version with IS-IS LSP PDU handling fixes.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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