CVE-2026-120977Arista Networks EOS untrusted input in a security decision
CVE-2026-120977 is a untrusted input in a security decision in Arista Networks EOS, rated high (7.1 on CVSS 4.0).
Why this priority: High severity, with no exploitation signal yet.
Published · Updated · NVD status: Received
What it is
A security check relies on a value the attacker can set.
How it is reached
An attacker can exploit it from the same local network segment, without an account, and nobody has to click anything. Success also depends on conditions the attacker does not fully control.
What an attacker gains
A successful attack can change data or behaviour. In practice, this kind of flaw lets an attacker reach data or actions their role should not allow. The damage can spread past the vulnerable component into others.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- Upgrade Arista Networks EOS to a fixed version for your release line (4.32.0F, 4.33.0F).
- Segment the networks that can reach it.
Description from NVD
On affected platforms running Arista EOS with 802.1X with Dynamic Host Configuration Protocol (DHCP) device profiling enabled, a network-adjacent attacker can send a crafted DHCP packet to force the device to record a spoofed device profile. This may potentially allow the authenticated supplicant to acquire unauthorized access to a network segment with elevated privileges.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Permission checks in APIs and admin surfaces. The flaw sits between one role or tenant and another.
- Multi-tenant services. The flaw sits between one role or tenant and another.
Trust boundaries in play
- Local network segment. The attacker must share a network segment with the target.
- Isolation between components. The impact crosses out of the vulnerable component into others it should be isolated from.
- Between one role or tenant and another. An attacker who crosses it can reach data or actions their role should not allow.
Questions to answer about your own systems
- Where does Arista Networks EOS run in your systems, and at which version?
- Which network segments can reach them?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.