CVE-2023-49151Network attack vector

Contributor-level stored XSS via unsanitized shortcode attributes

Published Dec 14, 2023 · Updated Apr 28, 2026

Stored XSS in Simple Calendar – Google Calendar Plugin 3.2.7 and earlier allows remote authenticated users to inject scripts via shortcodes. The shortcode handlers accept user-supplied attributes without sufficient input sanitization and render them without sufficient output escaping. Contributor-level access is enough to plant the payload, which executes in the browser of any user who opens the affected page.

CVSS severity6.5
Medium
EPSS probability0.40%
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 Simple Calendar – Google Calendar Plugin 3.2.7 and earlier allows remote authenticated users to inject scripts via shortcodes. The shortcode handlers accept user-supplied attributes without sufficient input sanitization and render them without sufficient output escaping. Contributor-level access is enough to plant the payload, which executes in the browser of any user who opens the affected page.

The record

CVE
CVE-2023-49151
Published
Dec 14, 2023
Updated
Apr 28, 2026
Vendor
Xtendify Technologies
Product
Simple Calendar – Google Calendar Plugin
Classifications
CWE-79, CAPEC-592, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 14, 2023CVE 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=n/a <=3.2.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Xtendify Technologies · Simple Calendar – Google Calendar Pluginversion=n/a <=3.2.6

Published CVSS scores

6.5PatchstackCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
6.4WordfenceCVSS:3.1/AV:N/AC:L/PR:L/UI:N/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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