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CVE-2026-54804 melhorenvio CVE debrief

CVE-2026-54804 is a HIGH severity vulnerability (CVSS Score: 7.6) affecting the Melhor Envio plugin, versions up to 2.16.3. This vulnerability involves broken authentication for subscribers. Successful exploitation could allow an attacker to potentially gain unauthorized access or elevate privileges. The vulnerability was published on June 17, 2026, and immediately gained attention due to its potential impact on WordPress sites using the affected plugin. Users of this plugin should take immediate action to mitigate potential risks.

Vendor
melhorenvio
Product
Melhor Envio
CVSS
HIGH 7.6
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-17
Original CVE updated
2026-06-17
Advisory published
2026-06-17
Advisory updated
2026-06-17

Who should care

WordPress site administrators using the Melhor Envio plugin, especially those with subscriber-level access, should be aware of this vulnerability. Given the HIGH severity and potential for exploitation, immediate attention is required to secure affected installations.

Technical summary

The CVE-2026-54804 vulnerability is classified under CWE-288, indicating a broken authentication mechanism in the Melhor Envio plugin. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H suggests that the vulnerability can be exploited over the network with low attack complexity, requiring only low privileges. Successful exploitation could lead to confidentiality, integrity, and high availability impacts.

Defensive priority

High

Recommended defensive actions

  • Update the Melhor Envio plugin to a version beyond 2.16.3 immediately.
  • Review subscriber-level access and permissions on affected WordPress sites.
  • Implement additional monitoring for suspicious activity related to subscriber authentication.
  • Consider temporarily disabling subscriber access until the update can be applied.
  • Review and enhance overall WordPress site security measures.
  • Apply patches or updates as provided by the plugin vendor.
  • Consult with a WordPress security expert if immediate updates are not feasible.

Evidence notes

The information provided is based on data from official sources, including the CVE.org and NVD databases. The CVE was published and modified on June 17, 2026. Additional details were obtained from Patchstack, indicating their role in identifying the vulnerability.

Official resources

This debrief is based on publicly available data from reputable sources and is intended for informational purposes only.