CVE-2023-0874Public exploitNetwork attack vector

Administrator stored XSS via unescaped API key

Published Apr 10, 2023 · Updated Feb 11, 2025

Stored XSS in the Klaviyo WordPress plugin before 3.0.10 allows remote authenticated users to execute scripts via its Public API Key setting. The settings handler stores the Public API Key without sufficient sanitization, and the admin page renders it without adequate escaping. Administrator privileges and a site that disallows unfiltered_html, such as a multisite installation, are required; viewing the injected page triggers the script.

CVSS severity4.8
Medium
EPSS probability0.44%
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 Klaviyo WordPress plugin before 3.0.10 allows remote authenticated users to execute scripts via its Public API Key setting. The settings handler stores the Public API Key without sufficient sanitization, and the admin page renders it without adequate escaping. Administrator privileges and a site that disallows unfiltered_html, such as a multisite installation, are required; viewing the injected page triggers the script.

The record

CVE
CVE-2023-0874
Published
Apr 10, 2023
Updated
Feb 11, 2025
Vendor
Klaviyo, Inc.
Product
Klaviyo
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Apr 10, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 11, 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 <3.0.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Klaviyo, Inc. · Klaviyoversion=0 <3.0.10

Published CVSS scores

4.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:H/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
Privilegesadmin
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/JScript

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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