Detection Deficit: A Year in Review of 0-days Used In-The-Wild in 2019

Our effort on this began in earnest in the last quarter of 2019. Today we are beginning to publish the root cause analyses for 0-days exploited in the wild that we have completed. While we’re publishing some in bulk now to play “catch-up”, in the future we plan to post each one in a timely manner after it’s detected and disclosed. We think publishing technical details in a timely manner is important for transparency and so that the whole of the security community can make informed decisions and actions.

I’m really interested in 0-days exploited in the wild and what we, the security community, can learn about them to make 0-day hard. I explained some of Project Zero’s ideas and goals around in-the-wild 0-days in a November blog post.

CVE-2026-0300 is a pre-auth buffer overflow in the PAN-OS User-ID Authentication Portal giving unauthenticated root RCE on PA-Series and VM-Series firewalls, already exploited in the wild.

An analysis of CVE-2023-0266 as used in a modern in-the-wild Android exploit, dissecting the vulnerability, the exploitation strategy, and defensive lessons learned.

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To read the other parts of the series, see the introduction post.

Project Zero’s mission is to make 0-day hard. We often work with other companies to find and report security vulnerabilities, with the ultimate goal of advocating for structural security improvements in popular systems to help protect people everywhere.