What is CVE-2026-33204?

CVE-2026-33204 is a high-severity vulnerability in Kelvinmo Simplejwt, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-03-20.

How severe is CVE-2026-33204?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Kelvinmo Simplejwt

CVE-2026-33204

SimpleJWT is a simple JSON web token library written in PHP. Prior to version 1.1.1, an unauthenticated attacker can perform a Denial of Service via JWE header tampering when PBES2 algorithms are used. Applications that call JWE::decrypt()…

Vulnerability class: DoS (Denial of Service)

EPSS: 0.000 (14.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Kelvinmo Simplejwt — versions < 1.1.1

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

https://github.com/kelvinmo/simplejwt/security/advisories/GHSA-xw36-67f8-339x (x_refsource_CONFIRM)
https://github.com/kelvinmo/simplejwt/releases/tag/v1.1.1 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-33204?: CVE-2026-33204 is a high-severity vulnerability in Kelvinmo Simplejwt, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-03-20.
How severe is CVE-2026-33204?: High severity. CVSS v3 base score is 7.5 out of 10.