- Author
- Bob, Application Security Engineer, Safeguard.sh
- Published
- 11 February 2026
- Kind
- Vendor blog post, a security overview with a product pitch at the end
- Original
- safeguard.sh/resources/blog/bun-runtime-security-considerations
- Subject
- Software tools and craft
- Themes
- How things break
What it is
The author is an application security engineer at Safeguard.sh, a software supply chain security company. The post is aimed at teams choosing a runtime. It sets out where Bun's security boundaries lie. The post says it is not an argument against using Bun.
What it says
- The post says Bun's native Zig code means bugs could be memory safety issues.
- Zig is not memory safe in the way Rust is, the post says.
- Bun disables registry lifecycle scripts by default, better than npm, but direct dependencies still run.
- The bun.lockb binary lockfile is hard to read and diff, which makes auditing harder.
- Bun has no permission model like Deno's and no equivalent of Node.js's experimental policy system.
- Bun's built-in bundler, test runner and package manager reduce the number of dependencies.
- The post advises OS-level hardening, such as a dedicated user, capabilities, seccomp and containers.
What evidence it gives
The post offers argument and general technical description. It cites no benchmarks, vulnerability counts or tests of Bun. Its claims about security research coverage are stated without sources.
Interests and limits
Safeguard.sh sells dependency scanning, and the post closes with a section promoting it. Nothing was tested. The comparison reflects Bun as of the post's date.