# CVE-2026-121286: Security Advisory 0213

Status: published. Published: 2026-11-10. Updated: 2026-11-13.

On affected platforms running Arista EOS in multi-agent routing model with BGP Segment Routing Traffic Engineering (SR-TE) address family configured, a BGP peer can send crafted BGP packets to cause the BGP process to restart, disrupting all BGP sessions on the device.

## Remediation

- workaround: For complete mitigation guidance and assistance, customers are advised to contact the Arista Networks Technical Assistance Center (TAC) for support. (source: CNA: Arista)

## Affected products and versions

- Arista Networks / EOS: ≥ 4.36.0F; ≤ 4.36.2F (affected, custom); ≥ 4.35.0F; ≤ 4.35.6M (affected, custom); ≥ 4.34.0F; ≤ 4.34.8M (affected, custom); ≥ 4.33.0F; ≤ 4.33.10M (affected, custom); ≥ 4.32.0F; < 4.33.0F (affected, custom); ≥ 4.22.1F; < 4.32.0F (affected, custom). Source: CNA: Arista; platforms: 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6/XE7 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, ZTX-7200 Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance

## Severity and prioritization

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H; source: CNA: Arista

- CVSS 4.0: 6 (medium); CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N; source: CNA: Arista

- CVSS 4.0: 6 (medium); CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/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; source: NVD: psirt@arista.com

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H; source: NVD: psirt@arista.com

- CISA KEV: No listing in collected sources

- EPSS: 0.29% as of 2026-11-13; percentile 21.76%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-476

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://www.arista.com/en/support/advisories-notices/security-advisory/25035-security-advisory-0213 (CNA: Arista; vendor-advisory)

- https://www.arista.com/en/support/advisories-notices/security-advisory/25035-security-advisory-0213 (psirt@arista.com)

## Provenance

- CNA: Arista: https://www.cve.org/CVERecord?id=CVE-2026-121286; retrieved 2026-11-13; source updated 2026-11-13

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121286; retrieved 2026-11-13; source updated 2026-11-12

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-121286; retrieved 2026-11-13; source updated Not reported

Revision: f21e91a3d6507dac7d76bd6b662794b9e3824835841630e64e66093d1227f9bb

Canonical: https://y2.dev/cve/CVE-2026-121286

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