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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.002 (8.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 8th percentile — 8.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/neuvector/neuvector/security/advisories/GHSA-wcx5-mq6c-c54j (vendor-advisory)
- bugzilla.suse.com/show_bug.cgi (issue-tracking)
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.