CVE-2026-73460

Traffic loss via malformed IS-IS LSP processing

Published Sep 15, 2026 · Updated Sep 15, 2026

Denial of service in Arista EOS 4.36.0 through 4.36.1F allows remote attackers to cause traffic loss via malformed IS-IS LSP PDUs. Processing a malformed LSP PDU terminates the IS-IS graceful restart procedure prematurely instead of preserving protocol state. Exploitation requires Layer 2 access, enabled IS-IS graceful restart, and a restart event; the bounded consequence is traffic disruption without data disclosure or modification.

CVSS severity7.0
High
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Arista EOS 4.36.0 through 4.36.1F allows remote attackers to cause traffic loss via malformed IS-IS LSP PDUs. Processing a malformed LSP PDU terminates the IS-IS graceful restart procedure prematurely instead of preserving protocol state. Exploitation requires Layer 2 access, enabled IS-IS graceful restart, and a restart event; the bounded consequence is traffic disruption without data disclosure or modification.

The record

CVE
CVE-2026-73460
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
Arista Networks
Product
Arista EOS
Classifications
CWE-863, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.36.0 <=4.36.1F

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Arista Networks · Arista EOSversion=4.36.0 <=4.36.1F

Published CVSS scores

6.1Arista NetworksCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H
7.0Arista NetworksCVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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