Post SMTP: known security problems
28 known security problems reported for this WordPress plugin, with the affected versions, the fix and what to do.
Updated
In short
There are 28 known security problems on this page. Each one has a fixed version. Updating to version 4.0.2 or newer covers every fixed problem listed here.
Based on public reports. Check the plugin’s changelog. Watchfox AI may be wrong.
Get an email when your site is affected: install Watchfox AI (free)
A stranger could plant harmful code that runs for your visitors or admins (up to and including 4.0.1)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 4.0.1
- Fixed in
- 4.0.2
- What to do
- If your site has an affected version, update Post SMTP to version 4.0.2 or newer.
- Official ID
- CVE-2026-75962
- Report title
- Post SMTP <= 4.0.1 - Unauthenticated Stored DOM-Based Cross-Site Scripting via 'user_email' Parameter (Multisite Registration → Failed Email Log)
- First reported
- Sources
- Wordfence, seen
Anyone with an account on your site, even a basic one could do things on your site they should not be allowed to (from 4.0.0-beta.1 up to and including 4.0.0-beta.1)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- From 4.0.0-beta.1 up to and including 4.0.0-beta.1
- Fixed in
- 4.0.1
- What to do
- If your site has an affected version, update Post SMTP to version 4.0.1 or newer.
- Official ID
- CVE-2026-81278
- Report title
- Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App 4.0.0-beta.1 - Missing Authorization to Authenticated (Subscriber+) Settings Change
- First reported
- Sources
- Wordfence, seen
A stranger could plant harmful code that runs for your visitors or admins (up to and including 3.6.2)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 3.6.2
- Fixed in
- 3.6.3
- What to do
- If your site has an affected version, update Post SMTP to version 3.6.3 or newer.
- Official ID
- CVE-2026-48838
- Report title
- Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App <= 3.6.2 - Unauthenticated Stored Cross-Site Scripting
- First reported
- Sources
- Wordfence, seen
Someone could plant harmful code that runs for your visitors or admins (up to and including 3.0.0)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 3.0.0
- Fixed in
- 3.1.0
- What to do
- If your site has an affected version, update Post SMTP to version 3.1.0 or newer.
- Official ID
- CVE-2024-13362
- Report title
- Freemius <= 2.10.1 - Reflected DOM-Based Cross-Site Scripting via url Parameter
- First reported
- Sources
- Wordfence, seen
Anyone with an account on your site, even a basic one could do things on your site they should not be allowed to (up to and including 3.8.0)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 3.8.0
- Fixed in
- 3.9.0
- What to do
- If your site has an affected version, update Post SMTP to version 3.9.0 or newer.
- Official ID
- CVE-2026-2559
- Report title
- Post SMTP <= 3.8.0 - Missing Authorization to Authenticated (Subscriber+) Office 365 OAuth Configuration Overwrite
- First reported
- Sources
- Wordfence, seen
A stranger could plant harmful code that runs for your visitors or admins (up to and including 3.8.0)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 3.8.0
- Fixed in
- 3.9.0
- What to do
- If your site has an affected version, update Post SMTP to version 3.9.0 or newer.
- Official ID
- CVE-2026-3090
- Report title
- Post SMTP <= 3.8.0 - Unauthenticated Stored Cross-Site Scripting via 'event_type'
- First reported
- Sources
- Wordfence, seen
Anyone with an account on your site, even a basic one could do things on your site they should not be allowed to (up to and including 3.6.1)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 3.6.1
- Fixed in
- 3.6.2
- What to do
- If your site has an affected version, update Post SMTP to version 3.6.2 or newer.
- Official ID
- CVE-2025-12887
- Report title
- Post SMTP – Complete SMTP Solution with Logs, Alerts, Backup SMTP & Mobile App <= 3.6.1 - Missing Authorization to Authenticated (Subscriber+) OAuth Token Update
- First reported
- Sources
- Wordfence, seen
A stranger could take over your site as an admin
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 3.6.0
- Fixed in
- 3.6.1
- What to do
- If your site has an affected version, update Post SMTP to version 3.6.1 or newer.
- Official ID
- CVE-2025-11833
- Report title
- Post SMTP – Complete SMTP Solution with Logs, Alerts, Backup SMTP & Mobile App <= 3.6.0 - Missing Authorization to Account Takeover via Unauthenticated Email Log Disclosure
- First reported
- Sources
- Wordfence, seen
Anyone with an account on your site, even a basic one could do things on your site they should not be allowed to (up to and including 3.4.1)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 3.4.1
- Fixed in
- 3.4.2
- What to do
- If your site has an affected version, update Post SMTP to version 3.4.2 or newer.
- Official ID
- CVE-2025-9219
- Report title
- Post SMTP <= 3.4.1 - Missing Authorization to Authenticated (Subscriber+) Limited Plugin Option Update
- First reported
- Sources
- Wordfence, seen
Anyone with an account on your site, even a basic one could take over your site as an admin
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 3.2.0
- Fixed in
- 3.3.0
- What to do
- If your site has an affected version, update Post SMTP to version 3.3.0 or newer.
- Official ID
- CVE-2025-24000
- Report title
- Post SMTP <= 3.2.0 - Missing Authorization to Authenticated (Subscriber+) Account Takeover via Email Log Exposure
- First reported
- Sources
- Wordfence, seen
Someone who already has an admin account could read or change the data in your site’s database (up to and including 3.1.2)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 3.1.2
- Fixed in
- 3.1.3
- What to do
- If your site has an affected version, update Post SMTP to version 3.1.3 or newer.
- Official ID
- CVE-2024-13844
- Report title
- Post SMTP <= 3.1.2 - Authenticated (Administrator+) SQL Injection via columns Parameter
- First reported
- Sources
- Wordfence, seen
A stranger could plant harmful code that runs for your visitors or admins (up to and including 3.0.2)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 3.0.2
- Fixed in
- 3.1.0
- What to do
- If your site has an affected version, update Post SMTP to version 3.1.0 or newer.
- Official ID
- CVE-2025-0521
- Report title
- Post SMTP <= 3.0.2 - Unauthenticated Stored Cross-Site Scripting
- First reported
- Sources
- Wordfence, seen
Someone could do things on your site they should not be allowed to
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.9.11
- Fixed in
- 2.9.12
- What to do
- If your site has an affected version, update Post SMTP to version 2.9.12 or newer.
- Official ID
- CVE-2025-22800
- Report title
- Post SMTP <= 2.9.11 - Missing Authorization via regenerate_qrcode()
- First reported
- Sources
- Wordfence, seen
Someone who already has an admin account could read or change the data in your site’s database (up to and including 2.9.9)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.9.9
- Fixed in
- 2.9.10
- What to do
- If your site has an affected version, update Post SMTP to version 2.9.10 or newer.
- Official ID
- CVE-2024-52436
- Report title
- Post SMTP <= 2.9.9 - Authenticated (Administrator+) SQL Injection
- First reported
- Sources
- Wordfence, seen
Someone who already has an admin account could read or change the data in your site’s database (up to and including 2.9.3)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.9.3
- Fixed in
- 2.9.4
- What to do
- If your site has an affected version, update Post SMTP to version 2.9.4 or newer.
- Official ID
- CVE-2024-5207
- Report title
- POST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress <= 2.9.3 - Authenticated (Administrator+) SQL Injection
- First reported
- Sources
- Wordfence, seen
Someone could use it to harm your site
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.8.7
- Fixed in
- 2.8.8
- What to do
- If your site has an affected version, update Post SMTP to version 2.8.8 or newer.
- Official ID
- CVE-2023-6875
- Report title
- POST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress <= 2.8.7 - Authorization Bypass via type connect-app API
- First reported
- Sources
- Wordfence, seen
Someone could plant harmful code that runs for your visitors or admins (up to and including 2.8.6)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.8.6
- Fixed in
- 2.8.7
- What to do
- If your site has an affected version, update Post SMTP to version 2.8.7 or newer.
- Official ID
- CVE-2023-6629
- Report title
- POST SMTP Mailer <= 2.8.6 - Reflected Cross-Site Scripting via msg
- First reported
- Sources
- Wordfence, seen
A stranger could plant harmful code that runs for your visitors or admins (up to and including 2.8.7)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.8.7
- Fixed in
- 2.8.8
- What to do
- If your site has an affected version, update Post SMTP to version 2.8.8 or newer.
- Official ID
- CVE-2023-7027
- Report title
- POST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress <= 2.8.7 - Unauthenticated Stored Cross-Site Scripting via device
- First reported
- Sources
- Wordfence, seen
Someone who already has an admin account could read or change the data in your site’s database (up to and including 2.8.6)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.8.6
- Fixed in
- 2.8.7
- What to do
- If your site has an affected version, update Post SMTP to version 2.8.7 or newer.
- Official ID
- CVE-2023-6620
- Report title
- POST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress <= 2.8.6 - Authenticated (Administrator+) SQL Injection
- First reported
- Sources
- Wordfence, seen
A stranger could plant harmful code that runs for your visitors or admins (up to and including 2.7.0)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.7.0
- Fixed in
- 2.7.1
- What to do
- If your site has an affected version, update Post SMTP to version 2.7.1 or newer.
- Official ID
- CVE-2023-5958
- Report title
- POST SMTP Mailer <= 2.7.0 - Unauthenticated Stored Cross-Site Scripting
- First reported
- Sources
- Wordfence, seen
Someone who already has an admin account could read or change the data in your site’s database (before 2.6.1)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Before 2.6.1
- Fixed in
- 2.6.1
- What to do
- If your site has an affected version, update Post SMTP to version 2.6.1 or newer.
- Report title
- Post SMTP <= 2.6.0 - Authenticated (Administrator+) SQL Injection
- First reported
- Sources
- Wordfence, seen
Someone could plant harmful code that runs for your visitors or admins (from 2.1.2-beta.1 up to and including 2.5.7)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- From 2.1.2-beta.1 up to and including 2.5.7
- Fixed in
- 2.5.9-beta.1
- What to do
- If your site has an affected version, update Post SMTP to version 2.5.9-beta.1 or newer.
- Official ID
- CVE-2023-33999
- Report title
- Freemius SDK <= 2.5.9 - Reflected Cross-Site Scripting via fs_request_get
- First reported
- Sources
- Wordfence, seen
A stranger could plant harmful code that runs for your visitors or admins (up to and including 2.5.7)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.5.7
- Fixed in
- 2.5.8
- What to do
- If your site has an affected version, update Post SMTP to version 2.5.8 or newer.
- Official ID
- CVE-2023-3082
- Report title
- Post SMTP <= 2.5.7 - Unauthenticated Stored Cross-Site Scripting via Email
- First reported
- Sources
- Wordfence, seen
Someone could trick a logged-in admin into changing settings without knowing (up to and including 2.5.6)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.5.6
- Fixed in
- 2.5.7
- What to do
- If your site has an affected version, update Post SMTP to version 2.5.7 or newer.
- Official ID
- CVE-2023-3179
- Report title
- POST SMTP Mailer <= 2.5.6 - Cross-Site Request Forgery to Account Compromise
- First reported
- Sources
- Wordfence, seen
Someone could trick a logged-in admin into changing settings without knowing (up to and including 2.5.6) (2)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.5.6
- Fixed in
- 2.5.7
- What to do
- If your site has an affected version, update Post SMTP to version 2.5.7 or newer.
- Official ID
- CVE-2023-3178
- Report title
- POST SMTP Mailer <= 2.5.6 - Cross-Site Request Forgery to Arbitrary Log Deletion
- First reported
- Sources
- Wordfence, seen
Someone who already has an admin account could make your server visit other addresses on their behalf
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.1.6
- Fixed in
- 2.1.7
- What to do
- If your site has an affected version, update Post SMTP to version 2.1.7 or newer.
- Official ID
- CVE-2022-2352
- Report title
- Post SMTP <= 2.1.6 - Authenticated (Administrator+) Blind Server-Side Request Forgery
- First reported
- Sources
- Wordfence, seen
Someone could plant harmful code that runs for your visitors or admins (up to and including 2.1.3)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.1.3
- Fixed in
- 2.1.4
- What to do
- If your site has an affected version, update Post SMTP to version 2.1.4 or newer.
- Official ID
- CVE-2022-2351
- Report title
- Post SMTP Mailer/Email Log <= 2.1.3 - Authenticated (Admin+) Stored Cross-Site Scripting
- First reported
- Sources
- Wordfence, seen
Someone could trick a logged-in admin into changing settings without knowing (up to and including 2.0.20)
A trusted security source confirmed it. If your site has an affected version, fix it this week.
- Affected versions
- Up to and including 2.0.20
- Fixed in
- 2.0.21
- What to do
- If your site has an affected version, update Post SMTP to version 2.0.21 or newer.
- Official ID
- CVE-2021-4422
- Report title
- POST SMTP Mailer <= 2.0.20 - Cross-Site Request Forgery Bypass
- First reported
- Sources
- Wordfence, seen
Where this comes from
We collect these reports from public security sources and rewrite them in plain words. Each problem shows its sources and the date we first saw it. This page never says whether your own site is affected: only a check of your site’s versions can tell.
Get an email when your site is affected.
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