CVE-2026-19640: Auth Bypass (CVSS 4.2)

Description

On affected platforms running Arista EOS, an authenticated user with access to the gNMI (gRPC Network Management Interface) may receive incorrect authorization results, potentially allowing access beyond their currently assigned permissions. This issue was discovered internally by Arista and the company is not aware of any malicious uses of this issue in customer networks.

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CVSS v3.1 Score

4.2

MEDIUM

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

EPSS — Exploit Prediction

0.0019

Probability of exploitation

0.09%

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-863 Incorrect Authorization

References

Other References

https://www.arista.com/en/support/advisories-notices/security-advisory/24726-security-advisory-0170

Frequently Asked Questions

What is CVE-2026-19640? +

On affected platforms running Arista EOS, an authenticated user with access to the gNMI (gRPC Network Management Interface) may receive incorrect authorization results, potentially allowing access beyond their currently assigned permissions. This issue was discovered internally by Arista and the company is not aware of any malicious uses of this issue in customer networks. It has a CVSS v3.1 base score of 4.2 (MEDIUM).

How severe is CVE-2026-19640? +

CVE-2026-19640 has a CVSS v3.1 score of 4.2 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0019, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-19640? +

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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