Stored XSS in UBB.threads

published 2026-06-18 4mo ago modified 2026-10-25 17d ago also EUVD-2026-37882

cvss: 5.1; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits: 0; none known

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.

Is CVE-2026-54219 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 4mo ago (2026-06-18)

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.1	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
CNA	4.0	5.1	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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

UBB Systems UBB.threads

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

ubbcentral.com /
product
cert.pl /en/posts/2026/06/CVE-2026-54219
third-party-advisory

Sources

CVE List CVE-2026-54219
NVD CVE-2026-54219

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