CVE-2026-11907

Stream <= 4.2.0 - Missing Authorization to Authenticated (Subscriber+) Sensitive Information Disclosure via Heartbeat API

2026-08-06 16:25
Yat

Strategic Overview

Status
Patched in 4.2.1
Affected Version
<= 4.2.0
CVSS
6.5Medium
Weakness type
CWE-862 · Missing Authorization
CVE
CVE-2026-11907
View all Stream – Activity Log & Audit Trail vulnerabilities

At a glance

CVE-2026-11907 is a medium-severity Missing Authorization vulnerability in the Stream WordPress plugin, affecting versions <= 4.2.0. It carries a CVSS score of 6.5 (reachable over the network; low attack complexity; high confidentiality impact). Exploitation requires an authenticated account at Subscriber level or above. The issue is fixed in version 4.2.1; sites on affected versions should update now. Disclosed August 2026, reported by Yat.

Vulnerability Overview

The Stream plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 4.2.0. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with subscriber-level access and above, to access all Stream activity records via the Heartbeat API.

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 interaction from a victim user. A successful exploit has high impact on confidentiality.

CWE-862: Missing Authorization

Reaching this weakness in Stream <= 4.2.0 takes an account at Subscriber level or above. A missing authorization check means a function is reachable by anyone who can reach the endpoint, because the code never asks whether the caller is allowed to perform the action.

Any user who can reach the endpoint gets to run an action reserved for higher-privileged roles, from reading protected data to changing settings or content. For Stream the fix is 4.2.1: builds <= 4.2.0 are affected, anything from 4.2.1 onward is not.

Remediation

Update to version 4.2.1, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Stream 4.2.1 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

Related records

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