CVE-2021-47737Public exploitNetwork attack vector

Authenticated phishing via unsanitized message titles

Published Dec 23, 2025 · Updated Apr 7, 2026

Stored HTML injection in CSZ CMS 1.2.7 allows remote authenticated users to embed malicious links in private-message titles. The member/insertpm endpoint accepts the title POST parameter and stores attacker-supplied anchor markup that is rendered in Backend System Dashboard and Member Dashboard message views. A valid account and a recipient following the rendered link are required, bounding the direct effect to phishing or social engineering through trusted dashboard content.

CVSS severity5.1
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored HTML injection in CSZ CMS 1.2.7 allows remote authenticated users to embed malicious links in private-message titles. The member/insertpm endpoint accepts the title POST parameter and stores attacker-supplied anchor markup that is rendered in Backend System Dashboard and Member Dashboard message views. A valid account and a recipient following the rendered link are required, bounding the direct effect to phishing or social engineering through trusted dashboard content.

The record

CVE
CVE-2021-47737
Published
Dec 23, 2025
Updated
Apr 7, 2026
Vendor
CSZ CMS
Product
CSZ CMS
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 23, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 7, 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=1.2.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

CSZ CMS · CSZ CMSversion=1.2.7

Published CVSS scores

5.4VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
5.1VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001User Execution: Malicious Link

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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