CVE-2023-39543Network attack vector

Unauthenticated browser script execution

Published Aug 21, 2023 · Updated Oct 4, 2024

Cross-site scripting in LuxCal Web Calendar before 5.2.3M or 5.2.3L allows remote attackers to run script in a user's browser. Neither LuxSoft nor JPCERT/CC identifies the affected request parameter or the server-side output operation that places attacker-controlled input into a rendered page. Exploitation is unauthenticated but requires a user to load the affected content, allowing script execution in that user's browser context.

CVSS severity6.1
Medium
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in LuxCal Web Calendar before 5.2.3M or 5.2.3L allows remote attackers to run script in a user's browser. Neither LuxSoft nor JPCERT/CC identifies the affected request parameter or the server-side output operation that places attacker-controlled input into a rendered page. Exploitation is unauthenticated but requires a user to load the affected content, allowing script execution in that user's browser context.

The record

CVE
CVE-2023-39543
Published
Aug 21, 2023
Updated
Oct 4, 2024
Vendor
LuxSoft
Product
LuxCal Web Calendar
Classifications
CWE-79
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 21, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=prior to 5.2.3L (SQLite version)
  2. Affected versionversion=prior to 5.2.3M (MySQL version)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

LuxSoft · LuxCal Web Calendarversion=prior to 5.2.3L (SQLite version); version=prior to 5.2.3M (MySQL version)

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1JPCERT/CCCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3JPCERT/CCAV:N/AC:M/Au:N/C:N/I:P/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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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