CVE-2026-81766: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-c5mg-rwrq-r34j
Share
CVSS 6.6
CWE-269
Published
Advisory Summary

CVE-2026-81766 is a MODERATE (CVSS 6.6) security vulnerability vulnerability (CWE-269: Improper Privilege Management) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-81766 at a Glance

CVE Identifier CVE-2026-81766
GHSA Identifier GHSA-c5mg-rwrq-r34j
Severity MODERATE
CVSS v3.1 Base Score 6.6
CWE Classification CWE-269: Improper Privilege Management
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 6.6

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required High (PR:H)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-81766

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-81766, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-269: Improper Privilege Management, where the product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

The Really Simple Security WordPress plugin before 9.8.0 does not check that the user is allowed to install Really Simple Security WordPress plugin before 9.8.0 before installing one from a user-supplied URL, allowing an administrator of a subsite on a multisite network to install and execute arbitrary code in the network-shared Really Simple Security WordPress plugin before 9.8.0 directory, which WordPress otherwise reserves to the network administrator. Exploitation requires the network administrator to have enabled the Really Simple Security WordPress plugin before 9.8.0 administration menu for subsites, which is not the default.

References

NVD — CVE-2026-81766 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-81766
wpscan.com/vulnerability/948d7... WEB
https://wpscan.com/vulnerability/948d70a2-605e-4a83-8feb-eca4dbb5f948

Frequently Asked Questions

What is CVE-2026-81766?
CVE-2026-81766 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-269: Improper Privilege Management.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-81766?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-81766?
CVE-2026-81766 has a CVSS v3.1 base score of 6.6 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-81766?
CVE-2026-81766 is classified under CWE-269: Improper Privilege Management (The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.).
How can I check Maven dependencies for CVE-2026-81766?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-c5mg-rwrq-r34j",
  "modified" : "2026-08-31T15:34:39Z",
  "published" : "2026-08-30T09:30:24Z",
  "aliases" : [ "CVE-2026-81766" ],
  "details" : "The Really Simple Security  WordPress plugin before 9.8.0 does not check that the user is allowed to install Really Simple Security  WordPress plugin before 9.8.0 before installing one from a user-supplied URL, allowing an administrator of a subsite on a multisite network to install and execute arbitrary code in the network-shared Really Simple Security  WordPress plugin before 9.8.0 directory, which WordPress otherwise reserves to the network administrator. Exploitation requires the network administrator to have enabled the Really Simple Security  WordPress plugin before 9.8.0 administration menu for subsites, which is not the default.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-81766"
  }, {
    "type" : "WEB",
    "url" : "https://wpscan.com/vulnerability/948d70a2-605e-4a83-8feb-eca4dbb5f948"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-269" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-30T07:17:21Z"
  }
}