CVE-2026-53673: BuddyPress Authenticated Attackers Can Access Arbitrary Vulnerability

HIGH
Advisory Identifier: GHSA-j3j5-5m8v-7gvc
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CVSS 8.1
CWE-639
Published
Advisory Summary

CVE-2026-53673 is a HIGH (CVSS 8.1) authenticated attackers can access arbitrary vulnerability (CWE-639: Authorization Bypass Through User-Controlled Key) affecting BuddyPress libraries in the Packagist ecosystem. The issue involves authenticated attackers can access arbitrary private message threads via user_id request parameter. Remediation is available by upgrading affected packages to version 14.5.0.

CVE-2026-53673 at a Glance

CVE Identifier CVE-2026-53673
GHSA Identifier GHSA-j3j5-5m8v-7gvc
Severity HIGH
CVSS v3.1 Base Score 8.1
CWE Classification CWE-639: Authorization Bypass Through User-Controlled Key
Affected Product BuddyPress
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 8.1

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

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

How to Fix CVE-2026-53673

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

buddypress/buddypress fixed: 14.5.0 
Upgrade buddypress/buddypress to 14.5.0
Verify Direct and Transitive Dependencies

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

inspect dependencies for buddypress/buddypress

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-53673, inspect your project dependencies for BuddyPress:

inspect dependencies for buddypress/buddypress

Analyze the terminal output to locate any version of BuddyPress in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 14.5.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-639: Authorization Bypass Through User-Controlled Key, where the system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. In BuddyPress, 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

BuddyPress 14.4.0 contains an insecure direct object reference vulnerability in the messages REST API that allows authenticated attackers to access arbitrary private message threads by supplying a user_id parameter in the request. Attackers can pass another user's identifier to the get_item_permissions_check method, which validates the supplied user_id instead of the logged-in user and is reused by the update and delete handlers, to read, reply to, or delete any user's private messages.

CVE-2026-53673 Affected BuddyPress Versions

1 component(s)
Fixed Versions:
14.5.0
Product / Package Ecosystem Affected Versions Fixed Version
buddypress/buddypress
 Packagist
< 14.5.0
14.5.0

References

NVD — CVE-2026-53673 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53673
Security Fix Commit FIX COMMIT
https://github.com/buddypress/buddypress/commit/27d41e9749a878103b3a673b37dfc92b7f8f2cb7
BuddyPress Security Information SECURITY
https://buddypress.org
BuddyPress Source Repository REPOSITORY
https://github.com/buddypress/BuddyPress
wordpress.org/plugins/buddypress WEB
https://wordpress.org/plugins/buddypress
www.vulncheck.com/advisories/buddypre... WEB
https://www.vulncheck.com/advisories/buddypress-private-message-idor-via-rest-api-user-id-parameter

Frequently Asked Questions

What is CVE-2026-53673?
CVE-2026-53673 is a security vulnerability in BuddyPress involving Authenticated attackers can access arbitrary private message threads via user_id request parameter under CWE-639: Authorization Bypass Through User-Controlled Key.
Which BuddyPress versions are affected?
Affected versions include releases prior to 14.5.0 across affected packages: buddypress/buddypress.
What version fixes CVE-2026-53673?
Upgrading to 14.5.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is buddypress/buddypress affected?
Yes, buddypress/buddypress is affected in releases prior to 14.5.0. Upgrade your dependency to 14.5.0 or later.
What is the CVSS score of CVE-2026-53673?
CVE-2026-53673 has a CVSS v3.1 base score of 8.1 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-53673?
CVE-2026-53673 is classified under CWE-639: Authorization Bypass Through User-Controlled Key (The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.).
How can I check Packagist dependencies for CVE-2026-53673?
Run the dependency tree command: 'inspect dependencies for buddypress/buddypress'. 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-j3j5-5m8v-7gvc",
  "modified" : "2026-08-12T18:47:41Z",
  "published" : "2026-06-10T00:31:53Z",
  "aliases" : [ "CVE-2026-53673" ],
  "summary" : "BuddyPress: Authenticated attackers can access arbitrary private message threads via user_id request parameter",
  "details" : "BuddyPress 14.4.0 contains an insecure direct object reference vulnerability in the messages REST API that allows authenticated attackers to access arbitrary private message threads by supplying a user_id parameter in the request. Attackers can pass another user's identifier to the get_item_permissions_check method, which validates the supplied user_id instead of the logged-in user and is reused by the update and delete handlers, to read, reply to, or delete any user's private messages.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "buddypress/buddypress"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.5.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-53673"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/buddypress/buddypress/commit/27d41e9749a878103b3a673b37dfc92b7f8f2cb7"
  }, {
    "type" : "WEB",
    "url" : "https://buddypress.org"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/buddypress/BuddyPress"
  }, {
    "type" : "WEB",
    "url" : "https://wordpress.org/plugins/buddypress"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/buddypress-private-message-idor-via-rest-api-user-id-parameter"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-639" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-12T18:47:41Z",
    "nvd_published_at" : "2026-06-10T00:16:55Z"
  }
}