CVE-2026-121295: Arista Networks EOS · Improper Validation of Specified Quantity in Input
Affects Arista Networks EOSSource CVE Database V5
Not known to be exploited · CVSS 8.6 High : upgrade to 4.33.0F or 4.32.0F soon.
Data as of 10 Nov 2026, 20:32 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
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 or 4.32.0F.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Arista NetworksEOS | Affected
| Fixed in
|
AI-suggested
Upgrade affected Arista EOS devices to versions 4.32.0F or 4.33.0F or later, where the vulnerability is fixed. Since this is not a cloud service, remediation requires manual patching. No other mitigations or workarounds are specified.
Description
CVE-2026-121295 is a high-severity vulnerability in Arista Networks EOS affecting versions from 1.0.0 up to 4.36.2F. It involves improper validation of specified quantity in input for S-BFD PDUs, allowing an unauthenticated attacker to send a crafted PDU to an initiator device configured as an S-BFD peer. This can cause the kernel on the initiator device to crash and reboot unexpectedly. Fixed versions include 4.32.0F and 4.33.0F.