CVE-2026-6854

My Calendar <= 3.7.8 - Unauthenticated SQL Injection via 'mc_auth' and 'mc_host' Parameters

2026-07-07 23:19
Leonid Semenenko (lsemenenko)

Strategic Overview

Status
Patched in 3.7.9
Affected Plugin
My Calendar – Accessible Event Manager
Affected Version
<= 3.7.8
CVSS
7.5High
Weakness type
CWE-89 · Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
CVE
CVE-2026-6854
View all My Calendar – Accessible Event Manager vulnerabilities

At a glance

CVE-2026-6854 is a high-severity Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in the My Calendar WordPress plugin, affecting versions <= 3.7.8. It carries a CVSS score of 7.5 (reachable over the network; low attack complexity; high confidentiality impact). Exploitation requires no authentication. The issue is fixed in version 3.7.9; sites on affected versions should update now. Disclosed July 2026, reported by Leonid Semenenko (lsemenenko).

Vulnerability Overview

The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to time-based blind SQL Injection via the 'mc_auth' parameter in all versions up to, and including, 3.7.8 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality.

CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')

My Calendar <= 3.7.8 carries this weakness at mc_auth, and reaching it takes no account at all. SQL injection happens when request data is concatenated into a query instead of being bound as a parameter, letting an attacker change the structure of the statement rather than just its values.

A working injection can read any table the database user can see, which on a WordPress install means user records, password hashes and session or API secrets stored in options. For My Calendar the fix is 3.7.9: builds <= 3.7.8 are affected, anything from 3.7.9 onward is not.

Remediation

Update to version 3.7.9, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: My Calendar 3.7.9 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-6854https://www.wordfence.com/threat-intel/vulnerabilities/id/aa1ed81c-04cb-4ccd-8c30-b1d943730909https://nvd.nist.gov/vuln/detail/CVE-2026-6854

Related records

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