CVE-2026-33204

HIGH

SimpleJWT has an Unauthenticated Denial of Service via JWE header tampering

Title source: cna
STIX 2.1

Description

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.

References (2)

Scores

CVSS v3 7.5
EPSS 0.0004
EPSS Percentile 13.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-400
Status published
Products (2)
kelvinmo/simplejwt < 1.1.1 (2 CPE variants)
kelvinmo/simplejwt 0 - 1.1.1Packagist
Published Mar 20, 2026
Tracked Since Mar 21, 2026