Arista EOS PTP: unauthenticated traffic to a PTP-enabled port causes denial of service

CVSS 9.2CVE-2026-121370Firmware, BMC & network fabriccurated

Impact

An unauthenticated attacker who can reach a PTP-enabled port on an EOS switch can cause denial of service by sending traffic to it. The record does not say whether only the PTP service fails or the whole switch. PTP is often enabled in clusters that need tight clock sync for distributed training or storage, so losing it, or losing the switch, can disrupt jobs on every node behind that device.

Who can reach it

Unauthenticated, with network access to a port where PTP is enabled. Anything connected to that port can try it, including compute nodes on a PTP-enabled access port.

What to do

Upgrade EOS to the fixed release listed in Arista Security Advisory 0224. The record does not give the fixed versions. A switch image upgrade means draining traffic off each device in turn. Until then, limit PTP to the ports that actually need it.

References

https://nvd.nist.gov/vuln/detail/CVE-2026-121370 https://www.arista.com/en/support/advisories-notices/security-advisory/25046-security-advisory-0224

This entry is curated: imported from vendor advisories with machine assistance, not yet individually verified. Confirm against your vendor's advisory before acting, and report anything wrong.