CVE-2026-19804: Software Security Vulnerability Vulnerability
HIGHCVE-2026-19804 is a HIGH (CVSS 8.8) security vulnerability vulnerability (CWE-94: Improper Control of Generation of Code ('Code Injection')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.. Remediation is available in the latest vendor maintenance releases.
CVE-2026-19804 at a Glance
Security Impact
CVSS: 8.8
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:H).
How to Fix CVE-2026-19804
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.
Run the following command in your project directory to verify that all resolved dependencies use the patched release:
mvn dependency:treeHow to Check if You Are Affected
To determine whether your Java application is affected by CVE-2026-19804, inspect your build dependencies using the Maven Dependency Plugin:
mvn dependency:treeAnalyze 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-94: Improper Control of Generation of Code ('Code Injection'), where the product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. 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
References
Frequently Asked Questions
What is CVE-2026-19804?
Which Software versions are affected?
What version fixes CVE-2026-19804?
What is the CVSS score of CVE-2026-19804?
What CWE is associated with CVE-2026-19804?
How can I check Maven dependencies for CVE-2026-19804?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-fgx2-6hhq-hwhw",
"modified" : "2026-09-25T09:31:08Z",
"published" : "2026-09-25T09:31:08Z",
"aliases" : [ "CVE-2026-19804" ],
"details" : "The s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 260814 via the 'first_name' parameter parameter. This is due to insufficient sanitization of the first_name parameter via esc_refs(), which strips only regex backreferences and not PHP tags, before substitution into the eval'd Signup Tracking Codes template, combined with disclosure of the site-global proxy verification key that allows PayPal postback verification to be bypassed. This makes it possible for unauthenticated attackers to execute code on the server. Successful exploitation requires that the site administrator has configured a Signup Tracking Codes template containing the %%first_name%% placeholder (a documented, GUI-supported feature) and that the attacker has obtained the site-global proxy verification key, which is exposed in plaintext in the JSON response of any PayPal Checkout AJAX request on the target site.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
} ],
"affected" : [ ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-19804"
}, {
"type" : "WEB",
"url" : "https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-checkout-in.inc.php#L736"
}, {
"type" : "WEB",
"url" : "https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-return-in-subscr-or-wa-w-level.inc.php#L311"
}, {
"type" : "WEB",
"url" : "https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-return-in-subscr-or-wa-w-level.inc.php#L319"
}, {
"type" : "WEB",
"url" : "https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-return-in.inc.php#L47"
}, {
"type" : "WEB",
"url" : "https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-utilities.inc.php#L185"
}, {
"type" : "WEB",
"url" : "https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-utilities.inc.php#L92"
}, {
"type" : "WEB",
"url" : "https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/tracking-codes.inc.php#L71"
}, {
"type" : "WEB",
"url" : "https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/utilities.inc.php#L49"
}, {
"type" : "WEB",
"url" : "https://plugins.trac.wordpress.org/changeset?reponame=&old=3671073%40s2member&new=3671073%40s2member"
}, {
"type" : "WEB",
"url" : "https://www.wordfence.com/threat-intel/vulnerabilities/id/e87da8fa-04cc-4b9a-9dde-be7d4f2bd76e?source=cve"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-94" ],
"severity" : "HIGH",
"github_reviewed" : false,
"github_reviewed_at" : null,
"nvd_published_at" : "2026-09-25T08:16:40Z"
}
}