CVE-2026-73437: Arista Networks EOS · Insufficient Verification of Data Authenticity
Affects Arista Networks EOSSource CVE Database V5
Not known to be exploited · CVSS 9.6 Critical · fixed in 4.36.2F : patch Arista Networks EOS as a priority.
Data as of 30 Oct 2026, 20:25 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.36.2F, 4.35.6M, 4.34.8M +1
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade Arista Networks EOS to 4.36.2F, 4.35.6M, 4.34.8M or 4.33.10M.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Arista NetworksEOS | Affected
| Fixed in
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| Arista NetworksEOS | Affected
| Fixed in
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| Arista NetworksEOS | Affected
| Fixed in
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| Arista NetworksEOS | Affected
| Fixed in
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AI-suggested
If you cannot patch yet, consider restricting network access to DHCP relay agents and monitoring DHCP traffic for anomalies. Avoid relying on DHCP relay configurations that accept replies from untrusted sources.
Description
On affected platforms running Arista EOS with Dynamic Host Configuration Protocol (DHCP) relay configured, an unauthenticated attacker with network access could send a crafted DHCP reply packet from an IP address that is not configured as a helper address, and the relay agent would forward it to clients without validating the source. This could allow the attacker to supply clients with malicious network configuration parameters, potentially resulting in traffic interception or denial of service for affected clients.