# CVE-2026-120981: Arista EOS VPLS-BGP route advertisement disruption

Source: https://junglewise.ai/threats/cve-2026-120981-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-2026-120981 · Severity: medium · CVSS 5.3 · Published 2026-11-10

Arista EOS is a network operating system used in data center and enterprise switches to manage traffic across networks. When VPLS-BGP (a feature that connects multiple customer networks over a shared backbone) is enabled, an attacker with BGP access can disrupt the route advertisements that keep those customer networks connected, causing temporary outages or network instability.

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

## Quick answers

**Is CVE-2026-120981 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-120981 being exploited in the wild.

**How severe is CVE-2026-120981?** Medium severity, with a CVSS score of 5.3, published 10 November 2026.

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

**Is there a fix for CVE-2026-120981?** No fixed version is recorded yet. Operators should disable VPLS-BGP functionality if not required, or restrict BGP session establishment to trusted peers using access control lists and authentication mechanisms. 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-2026-120981 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-120981?** 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


Operators should disable VPLS-BGP functionality if not required, or restrict BGP session establishment to trusted peers using access control lists and authentication mechanisms.

## Technical details

CVE-2026-120981 is a missing resource release vulnerability (CWE-772) in the BGP agent of Arista EOS when VPLS-BGP is configured. An attacker with an established BGP session to a Provider Edge router can send specially crafted BGP packets to cause improper route advertisement handling of VPLS pseudowires, leading to route churn. The vulnerability requires prior authentication as a BGP peer and VPLS-BGP to be explicitly enabled; no fix version is stated in the advisory.

## Affected products

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

## 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)