The Rust team has published a new point release of Rust, 1.34.2. Rust is a programming language that is empowering everyone to build reliable and efficient software.

If you have a previous version of Rust installed via rustup, getting Rust 1.34.2 is as easy as:

rustup update stable

If you don't have it already, you can get rustup from the appropriate page on our website.

What's in 1.34.2 stable

Sean McArthur reported a security vulnerability affecting the standard library that caused the Error::downcast family of methods to perform unsound casts when a manual implementation of the Error::type_id method returned the wrong TypeId, leading to security issues such as out of bounds reads/writes/etc.

The Error::type_id method was recently stabilized as part of Rust 1.34.0. This point release destabilizes it, preventing any code on the stable and beta channels to implement or use it, awaiting future plans that will be discussed in issue #60784.

An in-depth explanation of this issue was posted in yesterday's security advisory. The assigned CVE for the vulnerability is CVE-2019-12083.