CVE-2026-33204
High
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.
SeverityHigh
CVSS7.5
Exploit probability—
ProductKelvinmo Simplejwt
PublishedMar 20, 2026
First seenMar 20, 2026
Weakness typeCWE-400Uncontrolled resource consumption
How to fix
Update
- kelvinmo simplejwt1.1.1 or later
- kelvinmo/simplejwt1.1.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| kelvinmo simplejwt | v < 1.1.1 | 1.1.1 |
| kelvinmo/simplejwtPackagist | v < 1.1.1 | 1.1.1 |
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