CVE-2023-23654Network attack vector

Stored XSS via unsanitized plugin settings

Published May 15, 2023 · Updated Apr 28, 2026

Stored XSS in the SparkPost plugin for WordPress 3.2.5 and earlier allows remote authenticated users to inject scripts through settings. The plugin stores administrator-supplied settings without sufficient input sanitization and renders them without adequate output escaping. Exploitation requires administrator-level access and either WordPress Multisite or disabled unfiltered_html; opening the stored page runs the script.

CVSS severity5.9
Medium
EPSS probability0.39%
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 the SparkPost plugin for WordPress 3.2.5 and earlier allows remote authenticated users to inject scripts through settings. The plugin stores administrator-supplied settings without sufficient input sanitization and renders them without adequate output escaping. Exploitation requires administrator-level access and either WordPress Multisite or disabled unfiltered_html; opening the stored page runs the script.

The record

CVE
CVE-2023-23654
Published
May 15, 2023
Updated
Apr 28, 2026
Vendor
SparkPost
Product
SparkPost
Classifications
CWE-79, CAPEC-592, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. May 15, 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 <=3.2.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

SparkPost · SparkPostversion=n/a <=3.2.5

Published CVSS scores

5.9Patchstack CNACVSS:3.1/AV:N/AC:L/PR:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC-592Stored XSS
T1059.007JavaScript/JScript

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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