VulnerabilityDeferred

CVE-2026-54221

UBB.threads is vulnerable to Reflected XSS.

MEDIUM 5.1EPSS 0.29%

Does this matter?

Lower severity and a low EPSS score (0.29%). Track it; it rarely justifies an emergency change on its own.

Description

UBB.threads is vulnerable to Reflected XSS. The application improperly handles user input in certain requests, enabling attackers to execute arbitrary JavaScript in the context of a victim's browser by tricking them into clicking a crafted link. Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 7.7.5 but may also affect other versions.

CVSS 4.0: 5.1 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/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/M
EPSS: 0.29% probability · 22th percentile
CISA KEV: Not listed
Weakness: CWE-79
Source: cvd@cert.pl

References

https://cert.pl/en/posts/2026/06/CVE-2026-54219
https://www.ubbcentral.com/

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.