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VulnerabilityCVE-2026-77191Published 2026-09-14

CVE-2026-77191 — Arista Networks EOS

low

As of 2026-09-15, CVE-2026-77191 is a LOW-severity vulnerability in Arista Networks EOS, CVSS v3.1 2.6, EPSS 0.1% (3.7th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-77191 as of 2026-09-15; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

CVSS v3.1
2.6/10Low
EPSS
0.1%Higher than 3.7% of scored CVEs
CISA KEV
NoNot in the KEV catalog
Tracked threats
0None linked yet
Priority
1.4/10Threadlinqs triage score
Published
Updated 2026-09-15
CVSS v3.1 2.6 (LOW) · CVSS v4.0 2.1 · EPSS 0.1% (higher than 3.7% of all scored CVEs) · Priority 1.4/10 · Published 2026-09-14

Last updated:

What is CVE-2026-77191?

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.

The record classifies CVE-2026-77191 under weakness class CWE-862. Its CVSS v3 base vector states that the flaw is reachable from an adjacent network, needs low-privilege credentials, needs no user interaction. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 21 days ago.

Severity and exploitation probability

CVSS v3.1 base score
2.6 — LOW
CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
CVSS v4.0 base score
2.1
CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
EPSS (FIRST)
0.1% probability of exploitation in the next 30 days, higher than 3.7% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
1.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-09-14, last modified 2026-09-15

Is CVE-2026-77191 being exploited?

It currently carries a trending score of 31 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-77191

No vendor patch reference has been recorded for CVE-2026-77191 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-77191

No threat campaign in the Threadlinqs corpus currently references CVE-2026-77191, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.

Other references