The Mailgun for WordPress plugin for WordPress is vulnerable to Server-Side Request Forgery (SSRF) via path traversal in versions up to and including 2.2.0. This is due to insufficient input validation in the add_list() function, which accepts user-controlled array keys from $_POST['addresses'], passes them through sanitize_text_field(). This makes it possible for unauthenticated attackers to make authenticated POST requests to any Mailgun API endpoint using the WordPress site's API key, including creating inbound email-forwarding routes that can intercept password reset emails, leading to administrator account takeover.
CVE-2026-78003
CRITICALPre-NVD 9.89.8—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-22. a secondary CVSS source baseline 9.8; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.8
- EG Score
- 9.8(high)
- EG Risk
- 49(Track)EG Risk 49/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity98% × 45%Exploitation1% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 1%
- EPSS %ILE
- 43%
- KEV
- Not listed
Published
August 22, 2026
Last Modified
August 22, 2026
References (9)
- security@wordfencehttps://plugins.trac.wordpress.org/browser/mailgun/tags/2.1.10/mailgun.php#L259
- security@wordfencehttps://plugins.trac.wordpress.org/browser/mailgun/tags/2.1.10/mailgun.php#L323
- security@wordfencehttps://plugins.trac.wordpress.org/browser/mailgun/tags/2.1.10/mailgun.php#L331
- security@wordfencehttps://plugins.trac.wordpress.org/browser/mailgun/tags/2.1.10/mailgun.php#L557
- security@wordfencehttps://plugins.trac.wordpress.org/browser/mailgun/trunk/mailgun.php#L259
- security@wordfencehttps://plugins.trac.wordpress.org/browser/mailgun/trunk/mailgun.php#L323
- security@wordfencehttps://plugins.trac.wordpress.org/browser/mailgun/trunk/mailgun.php#L331
- security@wordfencehttps://plugins.trac.wordpress.org/browser/mailgun/trunk/mailgun.php#L557
- security@wordfencehttps://www.wordfence.com/threat-intel/vulnerabilities/id/110e888d-69fc-4682-b908-2b62288c5227?source=cve
Vendor Advisories for CVE-2026-78003(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 11× in last 7d / 11× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-23 05:27 UTCGHSA enrichment
- 2026-08-23 01:28 UTCEG score recompute
- 2026-08-23 01:28 UTCGHSA enrichment
- 2026-08-23 00:19 UTCEPSS rescore
- 2026-08-22 21:30 UTCGHSA enrichment
- 2026-08-22 17:31 UTCGHSA enrichment
- 2026-08-22 13:32 UTCGHSA enrichment
- 2026-08-22 09:33 UTCEG score recompute
- 2026-08-22 09:33 UTCGHSA enrichment
- 2026-08-22 08:41 UTCEG score recompute
- 2026-08-22 08:40 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-78003?
CVE-2026-78003 is a critical vulnerability published on August 22, 2026. The Mailgun for WordPress plugin for WordPress is vulnerable to Server-Side Request Forgery (SSRF) via path traversal in versions up to and including 2.2.0. This is due to insufficient input validation in the addlist() function, which accepts user-controlled array keys from $POST['addresses'],…
When was CVE-2026-78003 disclosed?
CVE-2026-78003 was first published in the National Vulnerability Database on August 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-78003 actively exploited?
CVE-2026-78003 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 57.3% of all scored CVEs.
What is the CVSS score of CVE-2026-78003?
CVE-2026-78003 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-78003?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-78003, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-78003
Is Your Infrastructure Affected by CVE-2026-78003?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.