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Fencer Vulns
critical 9.8

CVE-2020-36727 json

Newsletter Manager <= 1.5.1 - Insecure Deserialization

published 2023-06-07 3 y ago modified 2026-06-17 4 mo ago also EUVD-2020-24169

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

The Newsletter Manager plugin for WordPress is vulnerable to insecure deserialization in versions up to, and including, 1.5.1. This is due to unsanitized input from the 'customFieldsDetails' parameter being passed through a deserialization function. This potentially makes it possible for unauthenticated attackers to inject a serialized PHP object.

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
22 mo ago

Exploit prediction

1.62% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • blog.nintechnet.com https://blog.nintechnet.com/insecure-deserialization-vulnerability-in-wordpress-newsletter-manager-plugin-unpatched/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • f1logic Newsletter Manager

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.