CVE-2021-47927Public exploitNetwork attack vector

Stored XSS via unsanitized forum name

Published May 10, 2026 · Updated May 10, 2026

Stored XSS in WP Symposium Pro 2021.10 allows remote authenticated users to inject scripts through a crafted forum name. The admin setup handler stores wps_admin_forum_add_name without sanitizing its HTML event-handler content, then renders it when the forum is opened. An authenticated session with access to the admin setup page is required, and opening the created forum executes the payload in a viewer's browser.

CVSS severity5.1
Medium
EPSS probability0.19%
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 WP Symposium Pro 2021.10 allows remote authenticated users to inject scripts through a crafted forum name. The admin setup handler stores wps_admin_forum_add_name without sanitizing its HTML event-handler content, then renders it when the forum is opened. An authenticated session with access to the admin setup page is required, and opening the created forum executes the payload in a viewer's browser.

The record

CVE
CVE-2021-47927
Published
May 10, 2026
Updated
May 10, 2026
Vendor
WP Symposium Pro
Product
WP Symposium Pro
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 10, 2026CVE publishedPublication date reported by the CVE source.
  2. May 10, 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=2021.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

WP Symposium Pro · WP Symposium Proversion=2021.10

Published CVSS scores

5.1VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
6.4VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:N/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')
T1059.007JavaScript/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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