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() on attacker-controlled JWEs using PBES2 algorithms are affected. This issue has been patched in version 1.1.1.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.005 (38.8th 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)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
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.