Auth bypass in Go Neuvector

CVE-2026-78426

The NeuVector JWT verifier accepts noncanonical Base64URL encodings of the same RSA signature field. An attacker holding a valid JWT that has not expired, but was logged out of NeuVector, can continue using the non-expired token with equivalent spelling of the RSA signature field until the token validity expires.

Vulnerability class: Broken Access Control

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-78426?
CVE-2026-78426 is a low-severity vulnerability in Go Neuvector, classified under Incorrect Authorization. CVSS score: 3.7/10. Published 2026-09-17.
How severe is CVE-2026-78426?
Low severity. CVSS v3 base score is 3.7 out of 10.