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GHSA-x8jh-xj3x-gx3c fast-float

GHSA-x8jh-xj3x-gx3c is a security vulnerability in fast-float. No vendor fix is recorded yet; mitigation options are listed below.

`fast-float` has multiple soundness issues

Also known asRUSTSEC-2024-0379
Published
Nov 12, 2024
Updated
Sep 10, 2026
Affected
1 pkg
Patched
None yet
Exploits
None indexed
Exploitation data as of Sep 10, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected
🦀fast-float

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.

Description

fast-float contains multiple soundness issues:

  1. Undefined behavior when checking input length, which has been merged but no package pubished.
  2. Many functions marked as safe with non-local safety guarantees

The library is also unmaintained.

Alternatives

For quickly parsing floating-point numbers third-party crates are generally no longer needed. A fast float parsing algorithm by the author of lexical has been merged into libcore. When requiring direct parsing from bytes and/or partial parsers, the fast-float2 fork of fast-float containing these security patches and reduces overall usage of unsafe.

Affected Packages

1 total
EcosystemPackageVulnerable rangeFix
🦀crates.iofast-floatall versionsNo fix

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for fast-float, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Remediation status

    No patched version of fast-float has shipped for GHSA-x8jh-xj3x-gx3c yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

  3. Mitigate without a patch

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-x8jh-xj3x-gx3c can be triaged on real exposure rather than presence alone.

Tailored to GHSA-x8jh-xj3x-gx3c. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

`fast-float` contains multiple soundness issues: 1. [Undefined behavior when checking input length](https://github.com/aldanor/fast-float-rust/issues/28), which has been merged but no package [pubished](https://github.com/aldanor/fast-float-rust/issues/35). 1. [Many functions marked as safe with non-local safety guarantees](https://github.com/aldanor/fast-float-rust/issues/37) The library is also unmaintained. ## Alternatives For quickly parsing floating-point numbers third-party crates are generally no longer needed. A fast float parsing algorithm by the author of `lexical` has been [me
O3 Security · Impact-Aware SCA

Is GHSA-x8jh-xj3x-gx3c in your dependencies?

O3 Security finds GHSA-x8jh-xj3x-gx3c across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-x8jh-xj3x-gx3c: fast-float | O3 Security