Cyber Resilience

CVE-2026-28099

High

Published: 05 March 2026

Published
05 March 2026
Modified
22 April 2026
KEV Added
Patch
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 0.0004 14.4th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-28099 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 JavaScript (T1059.007); ranked at the 14.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-15 (Information Output Filtering).

Deeper analysis

CVE-2026-28099 is an improper neutralization of input during web page generation vulnerability, classified as reflected cross-site scripting (XSS) under CWE-79, in the LambertGroup UberSlider Ultra (uberSlider_ultra) WordPress plugin. This issue affects versions from n/a through 2.3 inclusive. The vulnerability was published on 2026-03-05 with a CVSS v3.1 base score of 7.1 (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L).

Attackers can exploit this vulnerability remotely over the network with low complexity and no required privileges, though it necessitates user interaction such as clicking a malicious link or visiting a crafted page. Successful exploitation allows injection and execution of arbitrary JavaScript in the context of the victim's browser, potentially leading to theft of session cookies, defacement of the page, or other client-side attacks, with low impacts on confidentiality, integrity, and availability but a changed scope.

The Patchstack advisory provides details on this WordPress plugin vulnerability, including assessment and recommendations for mitigation.

EU & UK References

Vulnerability details

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in LambertGroup UberSlider Ultra uberSlider_ultra allows Reflected XSS.This issue affects UberSlider Ultra: from n/a through <= 2.3.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1059.007 JavaScript Execution
Adversaries may abuse various implementations of JavaScript for execution.
T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
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.
Why these techniques?

Reflected XSS directly enables arbitrary JavaScript execution in browser (T1059.007) leading to session hijacking (T1185) and web session cookie theft (T1539).

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

CVEs Like This One

CVE-2025-0598Shared CWE-79
CVE-2026-23525Shared CWE-79
CVE-2026-34686Shared CWE-79
CVE-2025-26874Shared CWE-79
CVE-2025-55289Shared CWE-79
CVE-2026-28405Shared CWE-79
CVE-2025-69386Shared CWE-79
CVE-2025-22331Shared CWE-79
CVE-2025-24629Shared CWE-79
CVE-2026-28756Shared CWE-79

Affected Assets

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires validation and neutralization of untrusted input before web page generation, blocking the reflected XSS payload in uberSlider_ultra.

prevent

Requires filtering of information outputs to remove or encode script content, preventing execution of attacker-injected JavaScript in the victim's browser context.

preventdetect

Provides mechanisms to detect and block malicious code (scripts) delivered via web requests or responses, mitigating exploitation of the unsanitized input.

References