Rust removes most memory safety bugs in safe code, which is a large share of serious vulnerabilities in C and C++ code bases. It does not remove logic flaws, injection, weak authorization, unsafe blocks or risky dependencies. It is one strong control, not a complete security program.
Does it remove memory bugs?
In safe code, mostly yes. Ownership rules checked at compile time block double free and use of moved values. The ONCD report says memory safe languages can eliminate most memory safety errors, and that no language removes every cybersecurity risk.
What about unsafe?
Unsafe unlocks five operations the compiler cannot check, including dereferencing raw pointers and calling unsafe functions. It does not turn off the borrow checker. Review each unsafe block and keep them few.
What about C libraries?
The Rust Reference says undefined behavior in another language reached through FFI affects the whole program. A Rust program that links a vulnerable C library inherits the risk.
Does it fix web bugs?
No. Cross-site scripting, SQL injection, CSRF and missing authorization are top entries in the 2025 CWE Top 25, and none of them is a memory safety weakness. Code in any language can have them.
Is integer overflow handled?
Not the same as memory errors. Overflow behavior depends on the build mode (see integer overflow in debug and release builds), so treat arithmetic on sizes and indexes with care and use checked operations where it matters.
What about dependencies?
Rust crates are third party code. Scan them, pin versions, and review what you add. A malicious or vulnerable crate is a supply chain problem that the language does not solve.
Will a rewrite pay off?
It can, for exposed components. Android's documentation expects Rust to be the preferred choice for most new native projects, while saying rewriting everything is not feasible. Measure your own bug history before deciding.
What about build and release security?
Language choice does not touch the pipeline. Stolen publishing tokens, unreviewed workflow changes and unpinned build steps are risks in any ecosystem. Apply the same controls to a Rust project that you would to any other: reviewed changes, protected branches, scoped credentials and verified artifacts.
How do I explain this to my manager?
A short version: memory safe languages remove one very common, very costly class of bug from new code, and the government and large vendor sources reviewed here recommend them for new development. They do not replace testing, dependency hygiene or access control. The plan is to use them where exposure is highest and keep the rest of the program in place.
Where to start
- Pick one self contained, exposed component.
- Build it in Rust with a narrow interface.
- Run the same tests and fuzzing you would for C.
- Compare bug counts and effort after a release or two.
Try it yourself
Click through it at your own pace, or open it full screen. Look at the third party packages a project pulls in, since those sit outside the language guarantee.
Quick check
Is Rust code free of vulnerabilities?
No. It removes a class of memory bugs in safe code, but logic errors, injection, unsafe blocks and dependency issues remain.
Safeguard's dependency scanning can inventory the third party packages a project pulls in, and a free scan is available at https://gold.safeguard.sh/scan.
Sources
- Back to the Building Blocks, ONCD, February 2024
- The Rust Programming Language, Unsafe Rust
- The Rust Reference, Behavior considered undefined
- 2025 CWE Top 25, MITRE
- Android memory safety documentation
Last reviewed: 19 October 2026.
