CVE-2026-121370: Arista Networks EOS · Unthrottled Resource Allocation
Affects Arista Networks EOSSource CVE Database V5
Not known to be exploited · CVSS 8.6 High · fixed in 4.33.0F : patch Arista Networks EOS soon.
Data as of 10 Nov 2026, 20:22 UTC
Thin evidence
One scorer or none| CNA (Arista) | CVSS 3.1 | 8.6 |
|---|---|---|
| CNA (Arista) | CVSS 4.0 | 9.2 |
- Patch
- Available – fixed in 4.33.0F, 4.32.0F, 4.31.0F +1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 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 10 Nov 2026.
What to do
Upgrade Arista Networks EOS to 4.33.0F, 4.32.0F, 4.31.0F or 4.30.0F.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Arista NetworksEOS | Affected
| Fixed in
|
AI-suggested
Upgrade affected Arista EOS devices to fixed versions 4.30.0F, 4.31.0F, 4.32.0F, or 4.33.0F or later. Since this is a software vulnerability, patching is the recommended and effective mitigation. No vendor advisory content contradicts this guidance.
Description
CVE-2026-121370 is a high-severity vulnerability in Arista Networks EOS affecting versions from 4.29.2F up to and including 4.34.1F. It involves improper allocation of resources without limits or throttling in the Precision Time Protocol (PTP) feature. An unauthenticated attacker with network access to a PTP-enabled port can cause a denial of service (DoS) by sending crafted traffic. The issue has been fixed in versions 4.30.0F, 4.31.0F, 4.32.0F, and 4.33.0F.