CVE-2026-16268

Newsletters <= 4.15 - Unauthenticated Server-Side Request Forgery

2026-07-30 00:00
Yaswanth Reddy Sunkara

Strategic Overview

Status
Patched in 4.16
Affected Plugin
Newsletters
Affected Version
<= 4.15
CVSS
7.2High
Weakness type
CWE-918 · Server-Side Request Forgery (SSRF)
CVE
CVE-2026-16268
View all Newsletters vulnerabilities

At a glance

CVE-2026-16268 is a high-severity Server-Side Request Forgery (SSRF) vulnerability in the Newsletters WordPress plugin, affecting versions <= 4.15. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 4.16; sites on affected versions should update now. Disclosed July 2026, reported by Yaswanth Reddy Sunkara.

Vulnerability Overview

The Newsletters plugin for WordPress is vulnerable to Server-Side Request Forgery in versions up to, and including, 4.15. This is due to missing validation of the SubscribeURL hostname before issuing a remote request in the SNS bounce handler, allowing arbitrary URLs to be requested via wp_remote_request. This makes it possible for unauthenticated attackers to make web requests to arbitrary locations originating from the web application by supplying a crafted SNS SubscriptionConfirmation payload.

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.

CWE-918: Server-Side Request Forgery (SSRF)

Reaching this weakness in Newsletters <= 4.15 takes no account at all. Server-side request forgery means the application fetches a URL supplied by the caller, turning the server into a proxy for requests the attacker could not make directly.

The request originates from inside the hosting network, which is how these flaws reach cloud metadata endpoints, internal admin panels and services that trust local traffic. For Newsletters the fix is 4.16: builds <= 4.15 are affected, anything from 4.16 onward is not.

Remediation

Update to version 4.16, 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: Newsletters 4.16 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

Related records

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