CVE-2026-27206Network attack vector

Object injection via unrestricted @type class instantiation

Published Feb 21, 2026 · Updated Feb 21, 2026

PHP object injection in Zumba Fitness Json Serializer for PHP before 3.2.3 allows remote attackers to instantiate classes via JSON. JsonSerializer::unserialize() trusts the @type field as a class name and constructs any autoloadable class without an allowlist. Exploitation requires attacker-controlled JSON and a reachable class with dangerous magic methods; a usable gadget chain permits code execution, file changes, data access, or a service crash.

CVSS severity8.1
High
EPSS probability0.74%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

PHP object injection in Zumba Fitness Json Serializer for PHP before 3.2.3 allows remote attackers to instantiate classes via JSON. JsonSerializer::unserialize() trusts the @type field as a class name and constructs any autoloadable class without an allowlist. Exploitation requires attacker-controlled JSON and a reachable class with dangerous magic methods; a usable gadget chain permits code execution, file changes, data access, or a service crash.

The record

CVE
CVE-2026-27206
Published
Feb 21, 2026
Updated
Feb 21, 2026
Vendor
Zumba Fitness, LLC
Product
Json Serializer for PHP
Classifications
CWE-502
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.2.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zumba Fitness, LLC · Json Serializer for PHPversion=< 3.2.3

Published CVSS scores

8.1GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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