CVE-2026-2559

5.3 MEDIUM 0.2% exploit odds No fix listed Auth & access Web app

What it is

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.

At a glance

Exploitability: Can be exploited over the network with a low-privilege account. High risk of data tampering.
Exploit odds: 0.2% chance of exploitation in the next 30 days (EPSS).
Fix: No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

2026-03-18 16:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 10:31 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.2% in the next 30 days (EPSS).
Severity: 5.3 MEDIUM (CVSS).
Fix: none linked yet, which raises it.

Details

Published: 2026-03-18 16:16 UTC
Last modified: 2026-06-17 10:31 UTC
Exploit probability: 0.2% · EPSS, next 30 days
Weakness: CWE-862 · Missing authorization
Record status: Deferred

Attack profile CVSS 3.1 · 5.3

Attack vector: Network
Complexity: High
Privileges needed: Low
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-2559.md and follow it. Check whether this project is affected by CVE-2026-2559. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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References

NVD record · CVE.org record