CVE-2026-84899Network attack vector

Contributor-level script execution via unescaped class_suffix attribute

Published Sep 5, 2026 · Updated Sep 6, 2026

Stored XSS in E4J s.r.l. VikWidgetsLoader 1.11.0 allows remote authenticated users to execute JavaScript through a crafted block. The Gutenberg server-side renderer places the class_suffix block attribute into an inline script without sanitization or output escaping. Contributor access is sufficient to save the payload, which runs in the browser of anyone viewing the post, including an administrator reviewing a pending submission.

CVSS severityUnavailable
Unscored
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in E4J s.r.l. VikWidgetsLoader 1.11.0 allows remote authenticated users to execute JavaScript through a crafted block. The Gutenberg server-side renderer places the class_suffix block attribute into an inline script without sanitization or output escaping. Contributor access is sufficient to save the payload, which runs in the browser of anyone viewing the post, including an administrator reviewing a pending submission.

The record

CVE
CVE-2026-84899
Published
Sep 5, 2026
Updated
Sep 6, 2026
Vendor
E4J s.r.l.
Product
VikWidgetsLoader
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.11.0 <1.12.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

E4J s.r.l. · VikWidgetsLoaderversion=1.11.0 <1.12.0

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Cross-Site Scripting (XSS)
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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