saadiqbal Post SMTP Plugin up to 3.8.0 on WordPress Configuration Options handle_office365_oauth_redirect authorization

Summaryinfo

A vulnerability described as problematic has been identified in saadiqbal Post SMTP Plugin up to 3.8.0 on WordPress. Affected by this vulnerability is the function handle_office365_oauth_redirect of the component Configuration Options Handler. Executing a manipulation can lead to authorization. This vulnerability appears as CVE-2026-2559. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in saadiqbal Post SMTP Plugin up to 3.8.0 on WordPress. It has been declared as problematic. This vulnerability affects the function handle_office365_oauth_redirect of the component Configuration Options Handler. The manipulation with an unknown input leads to a authorization vulnerability. The CWE definition for the vulnerability is CWE-862. The product does not perform an authorization check when an actor attempts to access a resource or perform an action. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

The Post SMTP plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the `handle_office365_oauth_redirect()` function in all versions up to, and including, 3.8.0. This is due to the function being hooked to `admin_init` without any `current_user_can()` check or nonce verification. This makes it possible for authenticated attackers, with Subscriber-level access and above, to overwrite the site's Office 365 OAuth mail configuration (access token, refresh token, and user email) via a crafted URL. The configuration option is used during wizard setup of Microsoft365 SMTP, only available in the Pro option of the plugin. This could cause an Administrator to believe an attacker-controlled Azure app is their own, and lead them to connect the plugin to the attacker's account during configuration after upgrading to Pro.

The weakness was presented by Michael Iden. The advisory is available at wordfence.com. This vulnerability was named CVE-2026-2559 since 02/15/2026. The exploitation appears to be difficult. The attack can be initiated remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 03/24/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• WordPress Plugin

Vendor

• saadiqbal

Name

• Post SMTP Plugin

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7
• 3.8.0

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Discussion