Is CVE-2026-2559 actively exploited?

No active exploitation of CVE-2026-2559 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-2559 be exploited remotely?

Yes. CVE-2026-2559 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-2559?

CVE-2026-2559 has a CVSS score of 5.3 (MEDIUM).

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MEDIUM

CVE-2026-2559

CWE-862Published: March 18, 2026· Updated: Mar 19, 2026

5.3

CVSS v3.1

EPSS:0.03%probability of exploitation in 30 daysPercentile:7.0th

Official Description

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.

NVD Source

Technical Analysis

CVE-2026-2559 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 5.3.