GHSA-566x-hhrf-qf8m
MEDIUMGHSA-566x-hhrf-qf8m is a medium-severity (CVSS 5.5) Use After Free vulnerability in ordered-float. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-566x-hhrf-qf8m is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
ordered_float:NotNan may contain NaN after panic in assignment operators
Blast Radius
ordered-float🦀ordered-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
After using an assignment operators such as NotNan::add_assign, NotNan::mul_assign, etc., it was possible for the resulting NotNan value to contain a NaN. This could cause undefined behavior in safe code, because the safe NotNan::cmp method contains internal unsafe code that assumes the value is never NaN. (It could also cause undefined behavior in third-party unsafe code that makes the same assumption, as well as logic errors in safe code.)
This was mitigated starting in version 0.4.0, by panicking if the assigned value is NaN. However, in affected versions from 0.4.0 onward, code that uses the NotNan value during unwinding, or that continues after catching the panic, could still observe the invalid value and trigger undefined behavior.
The flaw is fully corrected in versions 1.1.1 and 2.0.1, by ensuring that the assignment operators panic without modifying the operand, if the result would be NaN.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | ordered-float | ≥ 2.0.0&&< 2.0.1 | 2.0.1 |
| 🦀crates.io | ordered-float | ≥ 0.2.2&&< 1.1.1 | 1.1.1 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ordered-float. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update ordered-float to 2.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-566x-hhrf-qf8m is resolved across your whole dependency graph.
Workarounds
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 pinpoints whether GHSA-566x-hhrf-qf8m is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-566x-hhrf-qf8m. 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-566x-hhrf-qf8m in your dependencies?
O3 detects GHSA-566x-hhrf-qf8m across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.