2.6

CVE-2026-77191: All of the CVEs covered in this advisory apply to affected platforms running Arista EOS with 802.1X authentication and authorization enabled and Access Control Lists (ACLs) configured for per-supplicant policy enforcement. An authenticated supplicant on an

Awaiting analysis
Published 14-09-2026Last modified 15-09-2026

Vulnerability summary

CVE-2026-77191 is a low (CVSS 2.6) Missing Authorization vulnerability in arista networks eos. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12.2% of scored vulnerabilities.

Overall risk
10/100
0100
Low · default modelHow is this calculated?
CVSS score
2.6/10
010
Low · v3.1 (CVE.org)
EPSS score
0.22%
0%100%
Low · +0.08 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 14-09-2026
    PublishedVulnerability first disclosed.
  2. 15-09-2026
    Last modifiedVulnerability information updated.

Description

An authenticated supplicant on an adjacent network may bypass intended network authorization policy and send unrestricted traffic during a brief window (milliseconds to seconds) between the completion of the authentication phase and the full enforcement of its assigned ACL.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.22%

Chance of exploitation in the next 30 days

Percentile

12%

Versus all other CVEs

30-day change

Increase +0.08 pp

From 0.14% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Arista networks1 product
  • eos≥ 4.35.0, ≤ 4.35.0.3F | ≥ 4.34.0, ≤ 4.34.5M | ≥ 0.0.0, ≤ 4.33.7.1M

1 vendor · 1 product

References

1 links