CVE-2026-73438: CWE-617 Reachable Assertion in Arista Networks EOS
On affected platforms running Arista EOS with Open Shortest Path First version 3 (OSPFv3) configured, an unauthenticated attacker on the same OSPFv3 broadcast domain can send a specially crafted set of packets that can cause the Ospf3 agent to restart unexpectedly. The crash results in the loss of all OSPFv3 adjacencies on the affected device and may disrupt routing across the broader OSPF domain until the agent recovers. This issue was reported externally by Dravanet Inc., and Arista is not aware of any malicious exploitation of this vulnerability in customer networks.
AI Analysis
Technical Summary
On Arista EOS platforms running OSPFv3, an unauthenticated attacker within the same broadcast domain can trigger a reachable assertion failure by sending specially crafted packets. This causes the OSPFv3 agent to restart unexpectedly, leading to loss of OSPFv3 adjacencies and potential routing disruption until the agent recovers. The vulnerability is identified as CWE-617 (Reachable Assertion) and affects EOS versions from 1.0.0 up to and including certain 4.x releases (<=4.36.1F). No vendor advisory or patch information is provided in the input data.
Potential Impact
The vulnerability causes a denial of service condition on the OSPFv3 routing agent by forcing it to restart. This leads to loss of all OSPFv3 adjacencies on the affected device and may disrupt routing across the OSPF domain until recovery. There is no impact on confidentiality or integrity reported. No known active exploitation has been observed.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, network operators should consider isolating OSPFv3 broadcast domains to trusted devices only to reduce exposure. Monitor for unexpected OSPFv3 agent restarts as an indicator of potential exploitation attempts.
CVE-2026-73438: CWE-617 Reachable Assertion in Arista Networks EOS
Description
On affected platforms running Arista EOS with Open Shortest Path First version 3 (OSPFv3) configured, an unauthenticated attacker on the same OSPFv3 broadcast domain can send a specially crafted set of packets that can cause the Ospf3 agent to restart unexpectedly. The crash results in the loss of all OSPFv3 adjacencies on the affected device and may disrupt routing across the broader OSPF domain until the agent recovers. This issue was reported externally by Dravanet Inc., and Arista is not aware of any malicious exploitation of this vulnerability in customer networks.
CVSS v3.1
Score 5.3medium
Affected software
Arista Networks
EOS
pkg:github/arista-networks/eosRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
On Arista EOS platforms running OSPFv3, an unauthenticated attacker within the same broadcast domain can trigger a reachable assertion failure by sending specially crafted packets. This causes the OSPFv3 agent to restart unexpectedly, leading to loss of OSPFv3 adjacencies and potential routing disruption until the agent recovers. The vulnerability is identified as CWE-617 (Reachable Assertion) and affects EOS versions from 1.0.0 up to and including certain 4.x releases (<=4.36.1F). No vendor advisory or patch information is provided in the input data.
Potential Impact
The vulnerability causes a denial of service condition on the OSPFv3 routing agent by forcing it to restart. This leads to loss of all OSPFv3 adjacencies on the affected device and may disrupt routing across the OSPF domain until recovery. There is no impact on confidentiality or integrity reported. No known active exploitation has been observed.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, network operators should consider isolating OSPFv3 broadcast domains to trusted devices only to reduce exposure. Monitor for unexpected OSPFv3 agent restarts as an indicator of potential exploitation attempts.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Arista
- Date Reserved
- 2026-08-12T16:39:35.977Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aaa659d55bf5e2cf5501be7
Added to database: 09/16/2026, 09:47:09 UTC
Last enriched: 09/16/2026, 10:01:54 UTC
Last updated: 09/17/2026, 03:07:34 UTC
Views: 15
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