Vulnerability · Published Sep 15, 2026 · Assigned by Arista
CVE-2026-73458On affected platforms running Arista EOS with authenticated Bidirectional Forwarding Detection (BFD) sessions configured, a specially crafted packet can cause the BFD session(s) to go down. This may result in undesirable network changes because various rou
High 8.2
In plain English
A high-severity security flaw in EOS from Arista Networks. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities).
Severity (CVSS 3.1)8.2High
Exploit odds (30 days)0.4%top 65.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
On affected platforms running Arista EOS with authenticated Bidirectional Forwarding Detection (BFD) sessions configured, a specially crafted packet can cause the BFD session(s) to go down. This may result in undesirable network changes because various routing protocols monitor status on BFD session(s).
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Arista Networks | EOS | 4.36.0 – through 4.36.1F4.35.0 – through 4.35.5M4.34.0 – through 4.34.7M4.33.0 – through 4.33.8M |
Weakness: CWE-303 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H