CVE-2023-40986Public exploitNetwork attack vector

Stored script execution via unsanitized Custom field

Published Sep 15, 2023 · Updated Jul 9, 2026

Stored XSS in Webmin 2.100 Usermin Configuration allows remote authenticated users to execute script in an administrator's browser. The Custom field in Edit Categories stores attacker-supplied HTML or script and renders it without neutralization when Reassign Module is opened. Access to the administrative interface is required to save the payload, and a subsequent interaction with Reassign Module executes it repeatedly in the user's Webmin origin.

CVSS severity5.4
Medium
EPSS probability0.47%
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 Webmin 2.100 Usermin Configuration allows remote authenticated users to execute script in an administrator's browser. The Custom field in Edit Categories stores attacker-supplied HTML or script and renders it without neutralization when Reassign Module is opened. Access to the administrative interface is required to save the payload, and a subsequent interaction with Reassign Module executes it repeatedly in the user's Webmin origin.

The record

CVE
CVE-2023-40986
Published
Sep 15, 2023
Updated
Jul 9, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Jul 9, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.4NVDCVSS:3.1/AV:N/AC:L/PR:L/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.

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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 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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