> In June 2025, I found a critical vulnerability in GitHub Copilot Chat (CVSS 9.6) that allowed silent exfiltration of secrets and source code from private repos, and gave me full control over Copilot’s responses, including suggesting malicious code or links.
> The attack combined a novel CSP bypass using GitHub’s own infrastructure with remote prompt injection. I reported it via HackerOne, and GitHub fixed it by disabling image rendering in Copilot Chat completely.
And parent is clearly responding to gp’s incorrect claims that “…without disclosing how they fixed it. Surely you could just do the base64 thing to an image url of your choice?” I’m sure there will be more attacks discovered in the future but gp is plain wrong on these points.
Please RTFA or at least RTFTLDR before you vote.
