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CVE-2026-73438: arista networks eos Reachable Assertion

CVSS: 7.0v4.0HighAwaiting analysis
Published 16-09-2026Last modified 16-09-2026

Vulnerability summary

CVE-2026-73438 is a high (CVSS 7.0) Reachable Assertion vulnerability in arista networks eos. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 14.9% of scored vulnerabilities.

Overall risk
28/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.0/10
010
High · v4.0 (CVE.org)
EPSS score
0.25%
0%100%
Low · +0.03 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 16-09-2026
    PublishedVulnerability first disclosed.
  2. 16-09-2026
    Last modifiedVulnerability information updated.

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 metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.25%

Chance of exploitation in the next 30 days

Percentile

15%

Versus all other CVEs

30-day change

+0.03 pp

From 0.21% on 22-09-2026

22-09-202622-10-2026
EPSS score
0.25%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Arista networks1 product
  • eos≥ 4.36.0F, ≤ 4.36.1F | ≥ 4.35.0F, ≤ 4.35.5M | ≥ 4.34.0F, ≤ 4.34.7M | ≥ 4.33.0F, ≤ 4.33.9M | ≥ 1.0.0, < 4.33.0F

1 vendor · 1 product

References

1 links