CVE-2025-12739 Cross-Site Scripting (XSS) in Looker's Extension Loader leading to Admin Account Compromise
An attacker with viewer permissions can execute scripts in an admin's browser via a malicious URL, leading to admin account compromise.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-12739?
CVE-2025-12739 is a high-severity cross-site scripting vulnerability in Google Cloud Looker, published on 24 Nov 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
An attacker with viewer permissions in Looker could craft a malicious URL that, when opened by a Looker admin, would execute an attacker-supplied script. Exploitation required at least one Looker extension installed on the instance.
Looker-hosted and Self-hosted were found to be vulnerable. This issue has already been mitigated for Looker-hosted instances. No user action is required for these.
Self-hosted instances must be upgraded as soon as possible. This vulnerability has been patched in all supported versions of Self-hosted. The versions below have all been updated to protect from this vulnerability. You can download these versions at the Looker download page https://download.looker.com/ : * 24.18.201+ * 25.0.79+ * 25.6.66+ * 25.12.7+ * 25.16.0+ * 25.18.0+ * 25.20.0+
Weakness: CWE-79
Which versions are affected by CVE-2025-12739?
How do I fix CVE-2025-12739?
No fix has been published for CVE-2025-12739 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-2025-12739 being exploited?
There is no known exploitation of CVE-2025-12739 in the wild and no public exploit code.
Sources
Also known as GHSA-mcm3-jr69-vvr3.