CVE-2025-39423Network attack vector

Stored XSS via missing nonce validation

Published Apr 17, 2025 · Updated Apr 28, 2026

Cross-site request forgery in Jenst Add to Header 1.0 and earlier allows remote attackers to inject stored scripts through forged requests. The plugin's settings-update path lacks correct nonce validation and accepts attacker-controlled header content that WordPress later renders. Exploitation requires an administrator to follow a crafted link or otherwise submit the forged action; the injected script then executes in visitors' browsers.

CVSS severity7.1
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site request forgery in Jenst Add to Header 1.0 and earlier allows remote attackers to inject stored scripts through forged requests. The plugin's settings-update path lacks correct nonce validation and accepts attacker-controlled header content that WordPress later renders. Exploitation requires an administrator to follow a crafted link or otherwise submit the forged action; the injected script then executes in visitors' browsers.

The record

CVE
CVE-2025-39423
Published
Apr 17, 2025
Updated
Apr 28, 2026
Vendor
Jenst
Product
Add to Header
Classifications
CWE-352, CAPEC-592, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 17, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 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=0 <=1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Jenst · Add to Headerversion=0 <=1.0

Published CVSS scores

7.1PatchstackCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-352Cross-Site Request Forgery (CSRF)
CAPEC-592Stored XSS
T1189Drive-by Compromise

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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