RUSTSEC-2026-0344

See a problem?
Please try reporting it to the source first.

Source

https://rustsec.org/advisories/RUSTSEC-2026-0344

Import Source

https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0344.json

JSON Data

https://api.osv.dev/v1/vulns/RUSTSEC-2026-0344

Published

2026-10-11T12:00:00Z

Modified

2026-10-13T10:45:04Z

Severity

7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator

Summary

Decompression bomb in `ruzstd`: a tiny input can exhaust memory (OOM)

Details

A crafted .zst input under 128 KB can force ruzstd to allocate several gigabytes at once, crashing the process with an out-of-memory condition. Since ruzstd is a decoder for untrusted input, a single small file is enough to take down anything decoding it.

The compressed size of a block was capped at 128 KB, but a compressed block's decompressed size was never checked against Block_Maximum_Size = min(Window_Size, 128 KiB) (RFC 8878). In execute_sequences the output was built with no running bound and no flush between blocks, so one block could expand to gigabytes — bypassing both the configured window-size limit and the block-by-block streaming that would otherwise release memory. (A related u32 counter overflow on such a block caused an additional panic.)

This is a denial of service only; memory access stays in bounds (no corruption, no RCE).

ruzstd is also built as a dependency of the Rust standard library via rustc-dep-of-std; in the toolchain it is used only to load zstd-compressed debug symbols, so the toolchain-side impact is limited.

Fixed in 0.9.1 (commit d3907c9), which enforces the per-block output bound. Upgrade to ruzstd >= 0.9.1.

Database specific

{
    "license":  "CC0-1.0"
}

References

Affected packages

crates.io / ruzstd

Package

Name: ruzstd; View open source insights on deps.dev
Purl: pkg:cargo/ruzstd

Affected ranges

Type: SEMVER
Events: Introduced

0.0.0-0

Fixed

0.9.1

Ecosystem specific

{
    "affected_functions":  null,
    "affects":  {
        "arch":  [],
        "functions":  [],
        "os":  []
    }
}