CVE-2025-39509Network attack vector

Stored script execution via unsanitized page input

Published May 16, 2025 · Updated Apr 28, 2026

Stored XSS in ThemeNcode TNC FlipBook 12.1.0 and earlier allows remote authenticated users to inject scripts into WordPress pages. Public advisories do not identify the affected input or rendering routine; they state that user input is insufficiently sanitized and escaped. Contributor-level access and a later page visit by another user are required for the stored script to execute in that user's browser.

CVSS severity6.5
Medium
EPSS probability0.25%
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 ThemeNcode TNC FlipBook 12.1.0 and earlier allows remote authenticated users to inject scripts into WordPress pages. Public advisories do not identify the affected input or rendering routine; they state that user input is insufficiently sanitized and escaped. Contributor-level access and a later page visit by another user are required for the stored script to execute in that user's browser.

The record

CVE
CVE-2025-39509
Published
May 16, 2025
Updated
Apr 28, 2026
Vendor
ThemeNcode LLC
Product
TNC FlipBook – PDF viewer for WordPress
Classifications
CWE-79, CAPEC-592, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 16, 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 <=12.1.0 changes=[{"at":"12.3.1","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

ThemeNcode LLC · TNC FlipBook – PDF viewer for WordPressversion=0 <=12.1.0 changes=[{"at":"12.3.1","status":"unaffected"}]

Published CVSS scores

6.5PatchstackCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
5.4NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC-592Stored XSS
T1059.007Command and Scripting Interpreter: JavaScript

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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