# CVE-2026-120980: Arista EOS BGP agent denial of service in VPLS-BGP

Source: https://junglewise.ai/threats/cve-2026-120980-on-affected-platforms-running-arista-eos-with-vpls-bgp-enabled  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10. Updated: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-120980 · Severity: medium · CVSS 5.3 · Published 2026-11-10

Arista EOS is network operating system used in high-performance routing switches. When VPLS-BGP (a technology for connecting multiple customer networks across a service provider backbone) is enabled, an attacker with an established BGP session can send a crafted packet that crashes the BGP agent, disrupting network connectivity and causing service outages for customers using that functionality.

Technologies: [Arista Eos](https://junglewise.ai/threats/technologies/eos). Vendors: [Arista](https://junglewise.ai/threats/vendors/arista).

## Quick answers

**Is CVE-2026-120980 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-120980 being exploited in the wild.

**How severe is CVE-2026-120980?** Medium severity, with a CVSS score of 5.3, published 10 November 2026.

**Which products and versions are affected?** Arista Eos 4.36.2F and below (4.36.x train), 4.35.6M and below (4.35.x train), 4.34.8M and below (4.34.x train), 4.33.10M and below (4.33.x train) on 7280R3, 7500R3, 7800R3 Series.

**Is there a fix for CVE-2026-120980?** No fixed version is recorded yet. Disable VPLS-BGP if not required, or restrict BGP session access to trusted peers through routing policy and access control lists until patched. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-120980 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-120980?** Check whether you run Arista Eos at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix


Disable VPLS-BGP if not required, or restrict BGP session access to trusted peers through routing policy and access control lists until patched.

## Technical details

A reachable assertion vulnerability (CWE-617) in the BGP agent allows an authenticated attacker on the network to trigger an unexpected restart by sending a specially crafted BGP packet. The vulnerability requires an established BGP session with a Provider Edge router running affected EOS versions with VPLS-BGP enabled. An exploit causes the BGP process to crash and restart, disrupting pseudowire signaling.

## Affected products

- Arista EOS 4.36.2F and below (4.36.x train), 4.35.6M and below (4.35.x train), 4.34.8M and below (4.34.x train), 4.33.10M and below (4.33.x train) on 7280R3, 7500R3, 7800R3 Series

## Timeline

- 2026-11-10: disclosed

## References

- [https://www.arista.com/en/support/advisories-notices/security-advisory/25036-security-advisory-0214](https://www.arista.com/en/support/advisories-notices/security-advisory/25036-security-advisory-0214)

## Related threats

- [Arista EOS path traversal in eAPI service](https://junglewise.ai/threats/cve-2026-121371-on-affected-eos-versions-with-the-eapi-service-enabled-a)
- [Arista EOS denial of service in PTP](https://junglewise.ai/threats/cve-2026-121370-on-affected-platforms-running-arista-eos-with-precision-time)
- [Arista EOS denial of service via resource exhaustion](https://junglewise.ai/threats/cve-2026-121369-on-affected-platforms-running-arista-eos-under-specific-link)
- [Arista EOS BFD authentication out-of-bounds write](https://junglewise.ai/threats/cve-2026-121368-on-affected-platforms-running-arista-eos-with-bidirectional)
- [Arista EOS RIPv2 silent enablement on management interfaces](https://junglewise.ai/threats/cve-2026-121367-on-affected-arista-eos-platforms-with-routing-information)