CVE-2026-54219 PUBLISHED

Stored XSS in UBB.threads

Assigner: CERT-PL
Reserved: 12.06.2026 Published: 18.06.2026 Updated: 18.06.2026

UBB.threads is vulnerable to Stored XSS via user posts and user profile fields. The application fails to properly sanitize user input, allowing low privileged attackers to inject arbitrary JavaScript that executes in a victim's browser upon viewing.

Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 7.7.5 but may also affect other versions.

Metrics

CVSS 4.0

CVSS Vector: CVSS: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 Score: 5.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	Low
Attack Complexity	Low	Integrity	Low	Integrity	Low
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	Low
User Interaction	Passive

CVSS 4.0

Product Status

Vendor	UBB Systems
Product	UBB.threads
Versions	Default: unknown affected from 0 to 7.7.5 (incl.)

Credits

Kamil Szczurowski (Securitum) finder
Michał Wnękowicz (Securitum) finder

References

Problem Types

CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') CWE

Impacts

CAPEC-592 Stored XSS