CVE-2026-121286: Null Dereference (CVSS 6.5)

Description

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.

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CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0029

Probability of exploitation

0.22%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-476 CWE-476

References

Other References

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

Frequently Asked Questions

What is CVE-2026-121286? +

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. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-121286? +

CVE-2026-121286 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0029, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-121286? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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