CVE-2023-52181Network attack vector

Unauthenticated PHP object injection via unsafe deserialization

Published Dec 31, 2023 · Updated Apr 28, 2026

PHP object injection in Presslabs Theme per user 1.0.1 and earlier allows remote attackers to instantiate objects via untrusted serialized data. Public CNA, vendor, and upstream materials do not identify the input parameter, handler, or deserialization call that accepts the data. No authentication or user interaction is required; further effects depend on a suitable PHP gadget chain in the WordPress environment.

CVSS severity9.8
Critical
EPSS probability0.65%
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 Presslabs Theme per user 1.0.1 and earlier allows remote attackers to instantiate objects via untrusted serialized data. Public CNA, vendor, and upstream materials do not identify the input parameter, handler, or deserialization call that accepts the data. No authentication or user interaction is required; further effects depend on a suitable PHP gadget chain in the WordPress environment.

The record

CVE
CVE-2023-52181
Published
Dec 31, 2023
Updated
Apr 28, 2026
Vendor
Presslabs
Product
Theme per user
Classifications
CWE-502, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 31, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 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=n/a <=1.0.1 changes=[{"at":"1.0.2","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Presslabs · Theme per userversion=n/a <=1.0.1 changes=[{"at":"1.0.2","status":"unaffected"}]

Published CVSS scores

10.0PatchstackCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
9.8NVDCVSS:3.1/AV:N/AC:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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