CVE-2026-78003Network attack vector

Administrator takeover via forged Mailgun API requests

Published Aug 22, 2026 · Updated Aug 25, 2026

SSRF in Mailgun for WordPress 2.2.0 and earlier allows remote attackers to send authenticated Mailgun API requests via crafted list addresses. The add_list() AJAX handler treats attacker-controlled keys from $_POST['addresses'] as API paths after only sanitize_text_field(), permitting traversal to other endpoints. No WordPress login is required, but the plugin must hold a usable Mailgun API key; crafted requests can create forwarding routes and intercept password-reset email for administrator takeover.

CVSS severity9.8
Critical
EPSS probability0.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

SSRF in Mailgun for WordPress 2.2.0 and earlier allows remote attackers to send authenticated Mailgun API requests via crafted list addresses. The add_list() AJAX handler treats attacker-controlled keys from $_POST['addresses'] as API paths after only sanitize_text_field(), permitting traversal to other endpoints. No WordPress login is required, but the plugin must hold a usable Mailgun API key; crafted requests can create forwarding routes and intercept password-reset email for administrator takeover.

The record

CVE
CVE-2026-78003
Published
Aug 22, 2026
Updated
Aug 25, 2026
Vendor
Mailgun
Product
Mailgun for WordPress
Classifications
CWE-918, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mailgun · Mailgun for WordPressversion=0 <=2.2.0

Published CVSS scores

9.8WordfenceCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo