6.1Medium

Google A2ui\/Web Core

CVE-2026-10032

The openUrl function in @a2ui/web_core passes an agent-controlled URL directly to window.open() without validating the URI scheme. A malicious agent can supply a javascript: URI as the url argument of a Button component's functionCall action. When the user clicks the rendered button, arbitrary JavaScript executes in the victim application's browser origin, constituting a stored/reflected XSS with Critical severity. No non-default configuration is required; the Basic Catalog is enabled by default.

What this means for your business

  • It affects Google A2ui\/Web Core. It matters if your company, or a supplier that handles your data, runs it.
  • An attacker can use it remotely, over a network, without a login, but only after tricking someone into an action such as opening a file or a link.
  • FIRST's prediction model gives it a 0.2% chance of attack attempts being seen in the next 30 days, ranking above 9% of all known flaws.

What to do

  1. 1Check whether your company or your suppliers run Google A2ui\/Web Core, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
6.1 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4
6.1
Weakness
CWE-79
Assigned by
cve-coordination@google.com

Dates

Published
2026-08-04
Last modified
2026-09-23
Sources
NVD

Affected products

  • Google A2ui\/Web Core0.9.0 - 0.10.2

As listed in the NVD configuration data. Not a statement about your estate.

References