# CVE-2026-120983: Security Advisory 0215

Status: published. Published: 2026-11-10. Updated: 2026-11-13.

On affected EOS platforms where 802.1x is configured in multi-host authenticated mode and the device is configured with Policy Based Routing (PBR), traffic from unauthenticated hosts may be forwarded to the destination configured in the PBR policies. This could potentially allow unauthenticated hosts access to networks. Additionally Layer 2 and Layer 3 control packets from unauthenticated hosts may get copied to the CPU.

## Remediation

- workaround: ip access-list PermitAnyAcl
  counters per-entry
  10 permit ip 20.1.1.0/24 any

(Workaround: Configure the PBR policy with specific, trusted address ranges rather than broad match rules) (source: CNA: Arista)

## Affected products and versions

- Arista Networks / EOS: ≥ 1.0.0; < 4.33.0F (affected, custom); ≥ 4.33.0F; ≤ 4.33.9M (affected, custom); ≥ 4.34.0F; ≤ 4.34.7M (affected, custom); ≥ 4.35.0F; ≤ 4.35.5M (affected, custom); ≥ 4.36.0F; ≤ 4.36.1F (affected, custom). Source: CNA: Arista; platforms: 710 Series, 720D Series, 720XP/722XPM Series, 7010TX Series, 7320X Series, 7060X/X2/X4/X5/X6/XE7 Series, 7260X/X3 Series, 7300X/X3 Series, 7050X3/X4 Series, 750X Series, 7250 Series, 7358X4 Series, 7368X4 Series, 7388X5 Series

## Severity and prioritization

- CVSS 3.1: 7.6 (high); CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L; source: CNA: Arista

- CVSS 4.0: 6.1 (medium); CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N; source: CNA: Arista

- CVSS 4.0: 6.1 (medium); CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: psirt@arista.com

- CVSS 3.1: 7.6 (high); CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L; source: NVD: psirt@arista.com

- CISA KEV: No listing in collected sources

- EPSS: 0.17% as of 2026-11-13; percentile 6.81%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-284

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://www.arista.com/en/support/advisories-notices/security-advisory/25037-security-advisory-0215 (CNA: Arista; vendor-advisory)

- https://www.arista.com/en/support/advisories-notices/security-advisory/25037-security-advisory-0215 (psirt@arista.com)

## Provenance

- CNA: Arista: https://www.cve.org/CVERecord?id=CVE-2026-120983; retrieved 2026-11-13; source updated 2026-11-13

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-120983; retrieved 2026-11-13; source updated 2026-11-12

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-120983; retrieved 2026-11-13; source updated Not reported

Revision: 03907eeb3f26dda170f623a6467c6d9a0156ae5e17bf23731b622ab27ee4178c

Canonical: https://y2.dev/cve/CVE-2026-120983

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