CVE-2023-4620Public exploitNetwork attack vector

Unauthenticated stored XSS via encoded booking names

Published Oct 16, 2023 · Updated May 2, 2025

Stored XSS in Booking Calendar before 9.7.3.1 allows remote attackers to execute script in an administrator's browser. The booking form accepts an HTML-encoded image payload in the First or Last Name field and later renders it without sufficient sanitization or escaping in the calendar overview. No authentication is required to store the payload, but an administrator must open the affected dashboard view; execution occurs in that browser session.

CVSS severity6.1
Medium
EPSS probability0.47%
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 Booking Calendar before 9.7.3.1 allows remote attackers to execute script in an administrator's browser. The booking form accepts an HTML-encoded image payload in the First or Last Name field and later renders it without sufficient sanitization or escaping in the calendar overview. No authentication is required to store the payload, but an administrator must open the affected dashboard view; execution occurs in that browser session.

The record

CVE
CVE-2023-4620
Published
Oct 16, 2023
Updated
May 2, 2025
Vendor
wpdevelop
Product
Booking Calendar
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 16, 2023CVE publishedPublication date reported by the CVE source.
  2. May 2, 2025Record 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 <9.7.3.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

wpdevelop · Booking Calendarversion=0 <9.7.3.1

Published CVSS scores

6.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/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 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 exploitPublished

Weakness, pattern, technique

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

Public exploit references

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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