CVE-2026-54219Network attack vector

Stored XSS via unsanitized posts and profile fields

Published Jun 18, 2026 · Updated Jun 18, 2026

Stored XSS in UBB Systems UBB.threads 7.7.5 and earlier allows remote authenticated users to execute JavaScript in a victim's browser. Posts and user profile fields are stored without proper sanitization and later rendered as executable script content. A low-privileged account can plant the payload, and execution occurs only when a victim views the affected post or profile.

CVSS severity5.1
Medium
EPSS probability0.29%
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 UBB Systems UBB.threads 7.7.5 and earlier allows remote authenticated users to execute JavaScript in a victim's browser. Posts and user profile fields are stored without proper sanitization and later rendered as executable script content. A low-privileged account can plant the payload, and execution occurs only when a victim views the affected post or profile.

The record

CVE
CVE-2026-54219
Published
Jun 18, 2026
Updated
Jun 18, 2026
Vendor
UBB Systems, LLC
Product
UBB.threads
Classifications
CWE-79, CAPEC-592, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 18, 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=0 <=7.7.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

UBB Systems, LLC · UBB.threadsversion=0 <=7.7.5

Published CVSS scores

5.1CERT.PLCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA: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')
CAPEC-592Stored XSS
T1059.007Command and Scripting Interpreter: JavaScript/JScript

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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