CVE-2026-103482

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

Published Oct 10, 2026 CVSS 3.1 · 5.4 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Simple Newsletter Plugin <= 4.3.10 - Unauthenticated Stored Cross-Site Scripting via Subscriber Custom Field via Manage Preferences Form + Campaign Preview noptin_key Pivot
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N'}

Subscriptions

No data.

Weaknesses

Sources

Status
PUBLISHED
Assigner
Wordfence
Published
Updated
Oct 11, 2026, 12:23 PM
Reserved
Sep 30, 2026, 4:24 PM
Status
Deferred
Published
Oct 10, 2026, 6:16 AM
Modified
Oct 13, 2026, 1:30 PM