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CVE-2026-73449

MEDIUM 5.9 ALL-YEARS

Published 2026-09-14 · Last modified 2026-09-15 · Arista · NVD: Awaiting Analysis

On affected platforms running Arista EOS with both 802.1X port authentication and the RADIUS proxy feature configured with dynamic authorization, a low-privileged attacker on an adjacent network segment who induces a RADIUS packet through a configured RADIUS proxy client can prevent RADIUS dynamic authorization messages, including Change-of-Authorization (CoA) and Disconnect-Requests as defined in RFC 5176, from being applied to locally authenticated 802.1X sessions. This allows an endpoint session that a RADIUS server or network access control system has ordered disconnected to remain authorized on the network. Both 802.1X port authentication with dynamic authorization and RADIUS proxy with dynamic authorization must be explicitly configured for a deployment to be exposed to this issue. This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.

LIMITED SIGNALS

No known exploitation, public exploit, or elevated probability at this time. Track for changes.

Exploitation likelihood

0.2%chance of exploitation in 30 days · 14th percentile

○ In CISA KEV○ Public exploit / PoC◆ SSVC: exploitation none, automatable no

Impact if exploited

5.9CVSS 4.0 · MEDIUM · CNA

  • ConfidentialityNone
  • IntegrityHigh
  • AvailabilityNone

What an attacker needs

  • ⚠Access: Must sit on the same / adjacent network
  • ⚠Privileges: Requires a low-privilege account
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable
  • ⚠Requirements: Specific conditions must be present

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

No public exploit or proof-of-concept code is catalogued for this CVE (no ExploitDB, Nuclei, or CISA-KEV entry). It may still exist — search GitHub or check the references below.

Affected

Vendors Arista Networks

Products Eos

Weakness (CWE)

  • CWE-290: Authentication Bypass by Spoofing

CVSS vector

CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:L

All CVSS metrics

  • MEDIUM 5.9 v3.1 · CNA Primary
    CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L
  • MEDIUM 5.9 v4.0 · CNA Primary
    CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:L
  • MEDIUM 5.9 v4.0 · NVD Secondary
    CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:L/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
  • MEDIUM 5.9 v3.1 · NVD Secondary
    CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L

References

Technical & other

Sources: NVD · CVE.org · EPSS