Security Advisory 0161
Published Sep 16, 2026
7.0
HIGHCVSS 4.0
EPSS 0.16%
Description
On affected platforms running Arista EOS with MLAG Dual Primary Detection configured, an unauthenticated attacker with access to the Dual Primary Detection network segment can send specially crafted packets to interfere with the dual-primary state. If the MLAG primary switch fails while these packets are present, the secondary switch incorrectly concludes it is in a dual-primary condition and err-disables its interfaces, leading to a traffic interruption.
Affected products
-
- Version 0.0.0StatusaffectedConstraints<4.33.0
- Version 4.33.0StatusaffectedConstraints<=4.33.9M
- Version 4.34.0StatusaffectedConstraints<=4.34.7.1M
- Version 4.35.0StatusaffectedConstraints<=4.35.5M
- Version 4.36.0StatusaffectedConstraints<=4.36.1F
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Arista Networks | EOS | unaffected |
|
No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
Vendor solution
The recommended resolution is to upgrade to a remediated software version at your earliest convenience.
Metrics
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:H
1 other source (NVD) ▾
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:H/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
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed Sep 17, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
Sep–Oct 2026- EPSS v5
Percentile over time
- EPSS v5
Table of values (2 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.16% (0.00160) | 4.56th | v5 (v2026.06.15) |
| Sep 16, 2026 | 0.13% (0.00132) | 3.14th | v5 (v2026.06.15) |
References (1)
- https://www.arista.com/en/support/advisories-notices/security-advisory/24717-security-advisory-0161 vendor-advisory
| Link | Providers | Tags |
|---|---|---|
| https://www.arista.com/en/support/advisories-notices/security-advisory/24717-security-advisory-0161 | vendor-advisory |
Change history (0)
No recorded changes yet.