CVE-2023-1166Public exploitNetwork attack vector

Stored XSS via unescaped subscription-form setting

Published Jun 27, 2023 · Updated Nov 27, 2024

Stored XSS in UltimatelySocial USM Premium before 16.3 allows remote authenticated users to inject script through plugin settings. The plugin stores a payload entered in the subscription-form “Text above the entry field” setting and renders it without sanitization or escaping when the settings page is reopened. Administrator privileges and a later visit to that page are required, allowing script execution in the visitor's browser even when unfiltered_html is disabled.

CVSS severity4.8
Medium
EPSS probability0.48%
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 UltimatelySocial USM Premium before 16.3 allows remote authenticated users to inject script through plugin settings. The plugin stores a payload entered in the subscription-form “Text above the entry field” setting and renders it without sanitization or escaping when the settings page is reopened. Administrator privileges and a later visit to that page are required, allowing script execution in the visitor's browser even when unfiltered_html is disabled.

The record

CVE
CVE-2023-1166
Published
Jun 27, 2023
Updated
Nov 27, 2024
Vendor
UltimatelySocial
Product
USM Premium
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jun 27, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 27, 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=0 <16.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

UltimatelySocial · USM Premiumversion=0 <16.3

Published CVSS scores

4.8NIST NVDCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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')
T1059.007JavaScript/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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