CVE-2023-4655Network attack vector

Browser script execution via HTML-rendered filename

Published Aug 31, 2023 · Updated Oct 1, 2024

Reflected XSS in InstantCMS 2 before 2.16.1 allows remote authenticated users to execute script through a crafted file name. The modern template's files.js passes the selected file input value to jQuery.html(), so markup in the filename is interpreted instead of displayed as text. An authenticated session and selection of a locally named file are required, and execution is confined to the affected page's browser context.

CVSS severity6.1
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

Reflected XSS in InstantCMS 2 before 2.16.1 allows remote authenticated users to execute script through a crafted file name. The modern template's files.js passes the selected file input value to jQuery.html(), so markup in the filename is interpreted instead of displayed as text. An authenticated session and selection of a locally named file are required, and execution is confined to the affected page's browser context.

The record

CVE
CVE-2023-4655
Published
Aug 31, 2023
Updated
Oct 1, 2024
Vendor
InstantCMS Team
Product
InstantCMS 2
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 31, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 1, 2024Record 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=unspecified <2.16.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

InstantCMS Team · InstantCMS 2version=unspecified <2.16.1

Published CVSS scores

4.3Huntr.dev CNACVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

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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