CVE-2026-73438: arista networks eos Reachable Assertion
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.
Timeline
- 16-09-2026PublishedVulnerability first disclosed.
- 16-09-2026Last 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- NVDNIST7.0HighCVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- NVDNIST5.3MediumCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
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
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected 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