CVE-2026-78997 Cross-site scripting in n/a
Attacker executes arbitrary JavaScript on any site via UC Browser's internal bridge, enabling account takeover.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-78997?
CVE-2026-78997 is a critical cross-site scripting vulnerability in n/a, published on 8 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
UC Browser for Android (package com.UCMobile.intl, version 13.7.8.1314) contains a Universal Cross-Site Scripting vulnerability that allows an attacker to execute arbitrary JavaScript in the context of any origin. An attacker hosts a specially crafted URL on a UC-owned domain (via a reflected XSS) that leverages the browser's internal JavaScript bridge to register a deferred callback, navigate the tab to a victim site, and then execute attacker-controlled code on that site when a login dialog is dismissed.
Weakness: CWE-79
Which versions are affected by CVE-2026-78997?
How do I fix CVE-2026-78997?
No fix has been published for CVE-2026-78997 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-78997 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-78997 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-4r5g-6487-f64m.