Vulnerability · Published Oct 10, 2026 · Assigned by Wordfence

CVE-2026-103482Simple Newsletter Plugin <= 4.3.10 - Unauthenticated Stored Cross-Site Scripting via Subscriber Custom Field via Manage Preferences Form + Campaign Preview noptin_key Pivot

Medium 5.4

In plain English

A medium-severity cross-site scripting in Noptin – Newsletter, New Post Notifications & Email Automation from picocodes. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).

Severity (CVSS 3.1)5.4Medium

Exploit odds (30 days)0.3%top 75.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

The Simple Newsletter Plugin – Noptin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'noptin_fields[<custom_field_merge_tag>] (e.g. first_name)' parameter in all versions up to, and including, 4.3.10 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The attack chain requires a published campaign post whose body contains a [[subscriber.*]] merge tag; the unauthenticated attacker first POSTs the entity-encoded payload to the public manage_preferences form (which issues its own nonce on the same page), then pivots execution by embedding their confirm_key in a campaign preview URL sent to a privileged user via social engineering.

Affected products (as reported)

Vendor	Product	Versions
picocodes	Noptin – Newsletter, New Post Notifications & Email Automation	0 – through 4.3.10

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

In plain English

Official description

Affected products (as reported)

References