CVE-2026-42754

High

Published: 27 May 2026

Published

27 May 2026

Modified

27 May 2026

KEV Added

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Patch

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CVSS Score v3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

EPSS Score 0.0015 4.2th percentile

Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-42754 is a high-severity Cross-site Scripting (CWE-79) vulnerability. Its CVSS base score is 7.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 4.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-32202

Vulnerability details

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in phbernard Favicon favicon-by-realfavicongenerator allows Reflected XSS.This issue affects Favicon: from n/a through <= 1.3.46.

CWE(s): CWE-79

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1539 Steal Web Session Cookie Credential Access

An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.

attack.mitre.org →

Why these techniques?

Reflected XSS in public-facing web plugin directly enables T1190 exploitation and T1539 session cookie theft via injected scripts.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1