CVE-2026-73455Network attack vector

Remote service interruption via malformed OSPFv3 packet

Published Sep 16, 2026 · Updated Sep 16, 2026

Denial of service in the OSPFv3 agent in Arista EOS 4.36.0.1F and earlier allows remote attackers to restart it with a crafted packet. Arista identifies an inconsistent packet-length parameter but has not disclosed the specific field or parser operation that mishandles it. Exposure requires OSPFv3 and at least one active neighbor; successful exploitation interrupts the routing agent without reported data disclosure or modification.

CVSS severity7.5
High
EPSS probability0.48%
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 the OSPFv3 agent in Arista EOS 4.36.0.1F and earlier allows remote attackers to restart it with a crafted packet. Arista identifies an inconsistent packet-length parameter but has not disclosed the specific field or parser operation that mishandles it. Exposure requires OSPFv3 and at least one active neighbor; successful exploitation interrupts the routing agent without reported data disclosure or modification.

The record

CVE
CVE-2026-73455
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
Arista Networks
Product
Arista EOS
Classifications
CWE-130, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=1.0.0 <4.33.0F
  2. Affected versionversion=4.33.0F <=4.33.8M
  3. Affected versionversion=4.34.0F <=4.34.6M
  4. Affected versionversion=4.35.0F <=4.35.4M
  5. Affected versionversion=4.36.0F <=4.36.0.1F

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Arista Networks · Arista EOSversion=1.0.0 <4.33.0F; version=4.33.0F <=4.33.8M; version=4.34.0F <=4.34.6M; version=4.35.0F <=4.35.4M; version=4.36.0F <=4.36.0.1F

Published CVSS scores

8.9Arista NetworksCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
7.5Arista NetworksCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-130Improper Handling of Length Parameter Inconsistency
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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