Quick answers
- Is CVE-2026-121294 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-121294 being exploited in the wild.
- How severe is CVE-2026-121294?
- 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), 4.35.6M and below (4.35.x), 4.34.8M and below (4.34.x), 4.33.10M and below (4.33.x), all 4.32.x, End of Support 4.31.x, 4.30.x, 4.29.x, 4.28.2F and later in 4.28.x.
- Is there a fix for CVE-2026-121294?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. 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-2026-121294 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-121294?
- 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.
Technical details
The vulnerability is an improper validation of input (CWE-1284) in the S-BFD reflector proxy component. An unauthenticated attacker on the network can send a crafted S-BFD PDU that causes the reflector to temporarily cease reflecting packets, resulting in S-BFD session timeouts. The vulnerability requires the S-BFD reflector proxy feature to be explicitly configured; devices without this configuration are not affected.
Affected products
- Arista EOS 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), all 4.32.x, End of Support 4.31.x, 4.30.x, 4.29.x, 4.28.2F and later in 4.28.x
Timeline
- 2026-11-10: disclosed