Only the latest release receives security fixes. Installed copies update themselves on their next launch, so keeping the app up to date is usually all you need to do.

Please don't open a public issue for a security problem. Instead, report it privately through GitHub private vulnerability reporting (the Report a vulnerability button on the repository's Security tab).

Include what you found, the version you tested and the steps or a sample file that reproduces it. You'll get a reply as soon as possible, and you'll be credited in the advisory once a fix is released unless you'd rather not be.

Image Optimizer ships third-party optimizers (listed in THIRD-PARTY-NOTICES.md). If the problem is in one of those tools rather than in Image Optimizer itself, please also report it to that project.