CVE-2026-73463Network attack vector

Revoked gRPC access via Authz policy race

Published Sep 16, 2026 · Updated Sep 16, 2026

Authorization bypass in Arista EOS 4.31.0F through 4.36.0.1F allows remote authenticated users to retain revoked access to gRPC interfaces. A race in gNSI Authz during policy rotation across multiple transports can leave the prior authorization policy active without reporting failure. Exposure requires gNSI Authz with multiple transports and valid credentials, and the retained access is limited to permissions removed by the rotated policy.

CVSS severity5.3
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in Arista EOS 4.31.0F through 4.36.0.1F allows remote authenticated users to retain revoked access to gRPC interfaces. A race in gNSI Authz during policy rotation across multiple transports can leave the prior authorization policy active without reporting failure. Exposure requires gNSI Authz with multiple transports and valid credentials, and the retained access is limited to permissions removed by the rotated policy.

The record

CVE
CVE-2026-73463
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
Arista Networks
Product
Arista EOS
Classifications
CWE-362, T1078
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.31.0F <=4.31.10M
  2. Affected versionversion=4.32.0F <=4.32.11M
  3. Affected versionversion=4.33.0F <=4.33.8M
  4. Affected versionversion=4.34.0F <=4.34.7M
  5. Affected versionversion=4.35.0F <=4.35.5M
  6. Affected versionversion=4.36.0F <=4.36.0.1F

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Arista Networks · Arista EOSversion=4.31.0F <=4.31.10M; version=4.32.0F <=4.32.11M; version=4.33.0F <=4.33.8M; version=4.34.0F <=4.34.7M; version=4.35.0F <=4.35.5M; version=4.36.0F <=4.36.0.1F

Published CVSS scores

6.0Arista NetworksCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
5.3Arista NetworksCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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