CVE-2026-19698

GutenKit <= 2.5.0 - Authenticated (Contributor+) Arbitrary CSS Injection

2026-09-01 00:00

Strategic Overview

Status: Patched in 2.5.1
Affected Plugin: GutenKit – Page Builder Blocks, Patterns, and Templates for Gutenberg Block Editor
Affected Version: <= 2.5.0
CVSS: 4.3Medium
Weakness type: CWE-74 · Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE: CVE-2026-19698

View all GutenKit – Page Builder Blocks, Patterns, and Templates for Gutenberg Block Editor vulnerabilities

At a glance

CVE-2026-19698 is a medium-severity Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerability in the GutenKit WordPress plugin, affecting versions <= 2.5.0. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Contributor level or above. The issue is fixed in version 2.5.1; sites on affected versions should update now. Disclosed September 2026, reported by Haitam Lazaar.

Vulnerability Overview

The GutenKit plugin for WordPress is vulnerable to CSS Injection in all versions up to, and including, 2.5.0. This is due to missing capability check on the saving user before persisting CSS style settings to post meta and block attributes, and missing trust validation before rendering those settings as an inline stylesheet. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary CSS into pages served to site visitors, enabling defacement, interface redressing, and forcing external resource loads.

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.

CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component

The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.

Remediation

Update to version 2.5.1, or a newer patched version

How does WordSec protect against this?

An attacker needs Contributor access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: GutenKit 2.5.1 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-19698 https://www.wordfence.com/threat-intel/vulnerabilities/id/348034d7-49e9-4db5-9707-7b55a83ba50d https://nvd.nist.gov/vuln/detail/CVE-2026-19698

Related records

Other vulnerabilities in GutenKit – Page Builder Blocks, Patterns, and Templates for Gutenberg Block Editor

CVSS Vector

4.3

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityLow
AvailabilityNone

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