AUGUST 4, 2026
Live Feed
Back to database
Case File

CVE-2026-21871

MEDIUM · CVSS 6.1 EPSS 0.24% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2026-01-08 · Last synced 2026-08-04

CyberRota Analysis

This is a medium severity vulnerability with a CVSS score of 6.1. It affects Java. Public exploit code or proof-of-concept references have been detected in its references.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-21871
Severity
MEDIUM
CVSS
6.1
EPSS
0.24%
Java

Original NVD Description

NiceGUI is a Python-based UI framework. From versions 2.13.0 to 3.4.1, there is a XSS risk in NiceGUI when developers pass attacker-controlled strings into ui.navigate.history.push() or ui.navigate.history.replace(). These helpers are documented as History API wrappers for updating the browser URL without page reload. However, if the URL argument is embedded into generated JavaScript without proper escaping, a crafted payload can break out of the intended string context and execute arbitrary JavaScript in the victim’s browser. Applications that do not pass untrusted input into ui.navigate.history.push/replace are not affected. This issue has been patched in version 3.5.0.

Related CVEs

Other vulnerabilities affecting the same vendor(s)