CVE-2024-27308: Mio is a Metal I/O library for Rust. (CVSS 7.5)

Mio is a Metal I/O library for Rust.

Mio is a Metal I/O library for Rust. When using named pipes on Windows, mio will under some circumstances return invalid tokens that correspond to named pipes that have already been deregistered from the mio registry. The impact of this vulnerability depends on how mio is used. For some applications, invalid tokens may be ignored or cause a warning or a crash. On the other hand, for applications that store pointers in the tokens, this vulnerability may result in a use-after-free. For users of Tokio, this vulnerability is serious and can result in a use-after-free in Tokio. The vulnerability is Windows-specific, and can only happen if you are using named pipes. Other IO resources are not affected. This vulnerability has been fixed in mio v0.8.11. All versions of mio between v0.7.2 and v0.8.10 are vulnerable. Tokio is vulnerable when you are using a vulnerable version of mio AND you are using at least Tokio v1.30.0. Versions of Tokio prior to v1.30.0 will ignore invalid tokens, so they are not vulnerable. Vulnerable libraries that use mio can work around this issue by detecting and ignoring invalid tokens.

Description from the National Vulnerability Database, published by GitHub

What it means for a small business

If your business uses mio, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.88%, higher than 59% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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