GHSA-8655-xgh5-5vvq — fast-float
GHSA-8655-xgh5-5vvq is a security vulnerability in fast-float. No vendor fix is recorded yet; mitigation options are listed below.
fast-fault has a segmentation fault due to lack of bound check
Real-World Exposure
fast-floatReal-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
In this case, the "fast_float::common::AsciiStr::first" method within the "AsciiStr" struct uses the unsafe keyword to reading from memory without performing bounds checking. Specifically, it directly dereferences a pointer offset by "self.ptr". Because of the above reason, the method accesses invalid memory address when it takes an empty string as its input. This approach violates Rust’s memory safety guarantees, as it can lead to invalid memory access if empty buffer is provided.
No patched version for fast-float crate has been released, but a patch is available in the fast-float2 fork.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | fast-float | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
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.
Remediation status
No patched version of fast-float has shipped for GHSA-8655-xgh5-5vvq yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-8655-xgh5-5vvq can be triaged on real exposure rather than presence alone.
Tailored to GHSA-8655-xgh5-5vvq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-8655-xgh5-5vvq in your dependencies?
O3 Security finds GHSA-8655-xgh5-5vvq across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.