Deserialization in Newsletters

CVE-2026-12583

The Newsletters WordPress plugin before 4.15 does not prevent deserialization of untrusted input that is stored through a public form, allowing unauthenticated attackers to inject a PHP object and, via a property-oriented gadget chain bundled with the Newsletters WordPress plugin before 4.15, write arbitrary files and execute code on the server.

Vulnerability class: Insecure Deserialization

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (45.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-12583: held from 0.006 to 0.006.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

  • Newsletters — versions 0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-12583?
CVE-2026-12583 is a high-severity vulnerability in Newsletters, classified under Deserialization of Untrusted Data. CVSS score: 8.1/10. Published 2026-07-14.
How severe is CVE-2026-12583?
High severity. CVSS v3 base score is 8.1 out of 10.