What is CVE-2026-35039?

CVE-2026-35039 is a critical-severity vulnerability in Nearform Fast-jwt, classified under Insufficient Verification of Data Authenticity. CVSS score: 9.1/10. Published 2026-04-06.

How severe is CVE-2026-35039?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Vulnerability in Nearform Fast-jwt

CVE-2026-35039

fast-jwt provides fast JSON Web Token (JWT) implementation. From 0.0.1 to before 6.2.0, setting up a custom cacheKeyBuilder method which does not properly create unique keys for different tokens can lead to cache collisions. This could cau…

EPSS: 0.000 (5.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Nearform Fast-jwt — versions >= 0.0.1, < 6.2.0

Weakness classification (CWE)

References

https://github.com/nearform/fast-jwt/security/advisories/GHSA-rp9m-7r4c-75qg (x_refsource_CONFIRM)
https://github.com/nearform/fast-jwt/commit/de121056c6415b58770c60640881eaec67ac4ceb (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-35039?: CVE-2026-35039 is a critical-severity vulnerability in Nearform Fast-jwt, classified under Insufficient Verification of Data Authenticity. CVSS score: 9.1/10. Published 2026-04-06.
How severe is CVE-2026-35039?: Critical severity. CVSS v3 base score is 9.1 out of 10.