Post SMTP <= 3.8.0 - Unauthenticated Stored Cross-Site Scripting via 'event_type'

2026-03-17 00:00

Strategic Overview

Status

Patched in 3.9.0

Affected PluginPost SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App

Affected Version<= 3.8.0

CVSS7.2High

CVECVE-2026-3090

View all Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App vulnerabilities

Vulnerability Overview

The Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘event_type’ parameter in all versions up to, and including, 3.8.0 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 vulnerability is only exploitable when the Post SMTP Pro plugin is also installed and its Reporting and Tracking extension is enabled.

Technical Analysis

REMEDIATION: Update to version 3.9.0, or a newer patched version --- IDENTIFIER: CWE-79 (Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

External References

https://www.cve.org/CVERecord?id=CVE-2026-3090 https://www.wordfence.com/threat-intel/vulnerabilities/id/3f8cbbbb-2089-4966-8fd3-da4f76fb2517

CVSS Vector

7.2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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