CVE Intelligence
Skip to main content
MEDIUM

CVE-2026-2559

CVE-2026-2559 — Post SMTP <= 3.8.0 - Missing Authorization to Authenticated (Subscriber+) Office 365 OAuth Configuration Overwrite

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.

Published Updated Sources: cvelistV5, Wordfence

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

0%

chance of exploitation in 30 days

Affects

saadiqbal

post_smtp_complete_email_deliverability_and_smtp_solution_with_email_logs_alerts_backup_smtp_mobile_app

CVSS base

5.3

MEDIUM

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

No

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Affected scope

The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.

Vendors (1)

saadiqbal

Products (1)

post smtp complete email deliverability and smtp solution with email logs alerts backup smtp mobile app

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactSource
5.3CVSS 3.1MEDIUM——cvelistV5

Weakness & attack patterns

  • CWE-862

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

  • T1211Exploitation for Defensive Evasion
  • T1542.002Pre-OS Boot: Component Firmware
  • T1556Modify Authentication Process

References

4 on the record

Elsewhere on this site

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.