SimpleJWT has an Unauthenticated Denial of Service via JWE header tampering

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-33204
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-03-20 23:16:45 UTC
Updated2026-04-10 01:25:08 UTC
DescriptionSimpleJWT 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.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS: 0.001150000 probability, percentile 0.301410000 (date 2026-04-15)

Problem Types: CWE-400 | CWE-400 CWE-400: Uncontrolled Resource Consumption

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Kelvinmo Simplejwt All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Kelvinmo Simplejwt affected < 1.1.1 Not specified

References

ReferenceSourceLinkTags
github.com/kelvinmo/simplejwt/releases/tag/v1.1.1 [email protected] github.com Product, Release Notes
github.com/kelvinmo/simplejwt/security/advisories/GHSA-xw36-67f8-339x [email protected] github.com Exploit, Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
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