Skip to main content

Post Smtp CVE-2023-6629

MEDIUM
Cross-site Scripting (XSS) (CWE-79)
2024-01-03 security@wordfence.com
6.1
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Output encoding, context-aware escaping
MITRE ATT&CK

2 techniques across 2 tactics: Initial Access, Execution

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 6.1 (MEDIUM). Attack characteristics: network attack vector, low complexity, no privileges required, user interaction required. EPSS exploitation probability: 0.50%.

Exploit ScenarioDerived

A remote attacker could inject malicious scripts into web pages viewed by other users by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 0.5% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Mar 28, 2026

The POST SMTP Mailer - Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the ‘msg’ parameter in all. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.

Earlier versions of this analysis (1)
v1 Mar 28, 2026 - 19:33 CVSS 6.1

The POST SMTP Mailer - Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the ‘msg’ parameter in all ve

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. The POST SMTP Mailer - Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the ‘msg’ parameter in all versions up to, and including, 2.8.6 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. Affected products include: Wpexperts Post Smtp.

Know when Post Smtp gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 6.1 MEDIUM
AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

Lifecycle Timeline

2
Patch released
Mar 28, 2026 - 19:33 nvd
Patch available
CVE Published
Jan 03, 2024 - 05:15 nvd
MEDIUM 6.1

DescriptionCVE.org

The POST SMTP Mailer - Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the ‘msg’ parameter in all versions up to, and including, 2.8.6 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

Executive ViewAI

Why It Matters

Organizations using all should be aware of moderate risk from CVE-2023-6629, a cross-site scripting vulnerability rated CVSS 6.1. Attackers could inject scripts to steal sessions or perform actions as authenticated users. A patch is available and should be applied during regular vulnerability management.

Business Impact: Low
Compensating Controls

Apply vendor patch. If patching is delayed: implement CSP headers, enable HttpOnly cookies, deploy WAF XSS rules.

Threat Intelligence Overview

EPSS Score
0.5%
Top 34% exploitable
Data Quality
4 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.5%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Defer
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact
Low

Priority Score

30
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +30
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.

Affected Products (CPE)CVE.org

cpe:2.3:a:wpexperts:post_smtp:*:*:*:*:*:wordpress:*:*
CVE-2023-6875 CRITICAL POC
9.8 Jan 11

The POST SMTP Mailer - Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress plugin for WordPress i

CVE-2023-3179 HIGH POC
8.8 Jul 17

The POST SMTP Mailer WordPress plugin before 2.5.7 does not have proper CSRF checks in some AJAX actions, which could al

CVE-2023-7027 HIGH POC
7.2 Jan 03

The POST SMTP Mailer - Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress plugin for WordPress i

CVE-2022-2352 HIGH POC
7.2 Sep 26

The Post SMTP Mailer/Email Log WordPress plugin before 2.1.7 does not have proper authorisation in some AJAX actions, wh

CVE-2023-6621 MEDIUM POC
6.1 Jan 03

The POST SMTP WordPress plugin before 2.8.7 does not sanitise and escape the msg parameter before outputting it back in

CVE-2023-5958 MEDIUM POC
6.1 Nov 27

The POST SMTP Mailer WordPress plugin before 2.7.1 does not escape email message content before displaying it in the bac

CVE-2022-2351 MEDIUM POC
4.8 Sep 16

The Post SMTP Mailer/Email Log WordPress plugin before 2.1.4 does not escape some of its settings before outputting them

CVE-2024-52436 HIGH
7.6 Nov 18

Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in Saad Iqbal Post SM

CVE-2024-5207 HIGH
7.2 May 30

The POST SMTP - The #1 WordPress SMTP Plugin with Advanced Email Logging and Delivery Failure Notifications plugin for W

CVE-2023-3082 HIGH
7.2 Jul 12

The Post SMTP plugin for WordPress is vulnerable to Stored Cross-Site Scripting via email contents in versions up to, an

CVE-2025-0521 HIGH
7.2 Feb 18

The Post SMTP plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the from and subject parameter in al

CVE-2026-48838 HIGH
7.1 Jun 15

Reflected or stored cross-site scripting in the Post SMTP WordPress plugin (versions 3.6.2 and earlier) allows unauthent

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy