CVE-2021-47905Public exploitNetwork attack vector

Administrator-session script execution via deletion reason

Published Jan 23, 2026 · Updated Jan 23, 2026

Stored cross-site scripting in MyBB Delete Account Plugin 1.4 allows remote authenticated users to execute script in an administrator's browser. In the affected code path, the deletion workflow stores the message field as deletereason, and the administrator listing renders it without effective HTML neutralization. A permitted forum member must submit the payload, and an administrator must later open the deleted-accounts page; execution is confined to that administrator's web session.

CVSS severity5.1
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored cross-site scripting in MyBB Delete Account Plugin 1.4 allows remote authenticated users to execute script in an administrator's browser. In the affected code path, the deletion workflow stores the message field as deletereason, and the administrator listing renders it without effective HTML neutralization. A permitted forum member must submit the payload, and an administrator must later open the deleted-accounts page; execution is confined to that administrator's web session.

The record

CVE
CVE-2021-47905
Published
Jan 23, 2026
Updated
Jan 23, 2026
Vendor
Vintagedaddyo
Product
MyBB Delete Account Plugin
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 23, 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=1.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Vintagedaddyo · MyBB Delete Account Pluginversion=1.4

Published CVSS scores

5.1VulnCheck CNACVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
6.1VulnCheck CNACVSS: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 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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