CVE-2020-36727Network attack vector

Unauthenticated PHP object injection via unsafe unserialize

Published Jun 7, 2023 · Updated Apr 8, 2026

Insecure deserialization in f1logic Newsletter Manager 1.5.1 and earlier allows remote attackers to inject PHP objects through a subscription form. The subscription.php handler passes the decoded customFieldsDetails request value to PHP unserialize without restricting object creation. No authentication is required; execution of attacker-chosen behavior depends on a suitable PHP gadget chain being present.

CVSS severity9.8
Critical
EPSS probability1.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insecure deserialization in f1logic Newsletter Manager 1.5.1 and earlier allows remote attackers to inject PHP objects through a subscription form. The subscription.php handler passes the decoded customFieldsDetails request value to PHP unserialize without restricting object creation. No authentication is required; execution of attacker-chosen behavior depends on a suitable PHP gadget chain being present.

The record

CVE
CVE-2020-36727
Published
Jun 7, 2023
Updated
Apr 8, 2026
Vendor
f1logic
Product
Newsletter Manager
Classifications
CWE-502, CAPEC-586, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 7, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 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=0 <=1.5.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

f1logic · Newsletter Managerversion=0 <=1.5.1

Published CVSS scores

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8WordfenceCVSS: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
CAPEC-586Object Injection
T1190Exploit Public-Facing Application

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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