KEV Intelligence

Vulnerability report

Active exploitation observed Confirmed confidence Not in CISA KEV

CVE-2026-4020

Gravity SMTP

RocketGenius / Gravity SMTP · * to <= 2.1.4

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Severity
CVSS 7.5 · High
Confidence
Confirmed
Exploit status
Observed in sensors
EPSS
41.8%
First observed
12 Jun 2026
Last observed
18 Aug 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-4020 is an unauthenticated vulnerability affecting RocketGenius Gravity SMTP. The Gravity SMTP plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 2.1.4....

Is it exploited?

Yes. KEV Intelligence sensors observed exploitation attempts with confirmed confidence.

Who is affected?

RocketGenius / Gravity SMTP * to <= 2.1.4.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

Gravity SMTP

The Gravity SMTP plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 2.1.4. This is due to a REST API endpoint registered at /wp-json/gravitysmtp/v1/tests/mock-data with a permission_callback that unconditionally returns true, allowing any unauthenticated visitor to access it.

When the ?page=gravitysmtp-settings query parameter is appended, the plugin's register_connector_data() method populates internal connector data, causing the endpoint to return approximately 365 KB of JSON containing the full System Report. This makes it possible for unauthenticated attackers to retrieve detailed system configuration data including PHP version, loaded extensions, web server version, document root path, database server type and version, WordPress version, all active plugins with versions, active theme, WordPress configuration details, database table names, and any API keys/tokens configured in the plugin.

Vendor Product Affected Status
RocketGenius Gravity SMTP Through 2.1.4 Affected
Published
31 Mar 2026
Exploited Since
12 Jun 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

wordpress php nuclei_scanner

CVE References

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

Wordfence

Recorded 17 Jun 2026

Independent exploitation attestation added to the KEV Intelligence record.

Active exploitation observed

KEV Intelligence sensor

First observed 12 Jun 2026

First-party sensor telemetry confirms matching exploitation attempts.

Proof of concept available

Nuclei Templates

Recorded 12 Jun 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source Added
KEV Intelligence First 2026-06-12 00:35 UTC
Wordfence 2026-06-17 10:28 UTC
The Shadowserver 2026-07-09 00:00 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Aggregate observations show the scale, recency, and distribution of activity without overstating sparse data.

121

Attempts observed

61

Unique attacker IPs

8

Attacker countries

BG · CA · DE · FR · NL · RO · UA · US

23

Sensors observed

Exploitation attempts over the last 70 days

Daily events observed by KEV Intelligence sensors

Updated 19 Aug 2026

0
1
6
19
5
0
2
1
0
0
3
0
1
1
19
5
7
1
15
23
1
4
188
2
6
0
0
4
4
4
4
4
0
4
12
16
8
4
2
0
4
4
0
5
5
6
3
5
4
2
4
3
3
0
2
3
4
10
3
9
1
14
4
2
3
3
2
8
5
0
11 Jun 25 Jun 9 Jul 23 Jul 19 Aug

First observed 12 Jun 2026 · Last observed 18 Aug 2026

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Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
1
User-Agents
13

Raw values available in Pro and Enterprise.

Virtual patch status

KEV Intelligence virtual patch guidance is available for this CVE.

AWS WAF Cloudflare ModSecurity

Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

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Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-4020.yaml 01 Jun 2026

Virtual Patch Detail

Compensating WAF rules for this CVE.

Available

Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEV Intelligence Enterprise users.

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Risk and context

Severity, weaknesses, and research context

CVSS v3.1

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

EPSS

41.8%

Weaknesses

Exposure of Sensitive Information to an Unauthorized Actor CWE-200

Recent mention · TheHackerNews

Hackers Exploit Gravity SMTP WordPress Plugin Bug to Expose API Keys

Threat actors are exploiting a recently patched security flaw impacting Gravity SMTP, a WordPress plugin that's installed on about 100,000 sites. The vulnerability, tracked as CVE-2026-4020 (CVSS score: 5.3), is a medium-severity information disclosure flaw that can allow...

Read full advisory

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Gravity SMTP WordPress Plugin - Sensitive Information Exposure

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. KEV confirmed by The Shadowserver

    Exploitation attested by an external source

  2. Virtual patch available

    Compensating WAF rule available to block exploitation

  3. KEV confirmed by Wordfence

    Exploitation attested by an external source

  4. Public PoC available

    Public proof-of-concept code published

  5. Observed by KEV Intelligence sensors

    Evidence-backed exploitation signal

  6. Indicators of compromise added (170)

    Indicators of compromise recorded

  7. Nuclei template available

    Scanner coverage available

  8. CVE published

    Vulnerability disclosed publicly

  9. CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-4020

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2026-4020",
  "confidence": "Confirmed",
  "cvss_score": 7.5,
  "cvss_estimated": false,
  "epss_score": 0.41825,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 121, "sensors": 23 }
}

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