RUSTSEC-2020-0082: ordered_float:NotNan may contain NaN after panic in assignment operators

What to do

1. See which version you have: cargo tree -i ordered-float (it also shows which of your dependencies pulls it in).
2. Update within your version requirement: cargo update -p ordered-float. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for example ordered-float = "2.0.1") or update the dependency that pulls it in.
3. Check again with cargo audit, or paste your Cargo.lock into our Cargo.toml checker.

Details from the advisory

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.

References

• Package: crates.io/crates/ordered-float
• Advisory: rustsec.org/advisories/RUSTSEC-2020-0082.html
• Web: github.com/reem/rust-ordered-float/pull/71

From the RustSec Advisory Database (CC0-1.0) via the OSV export, downloaded Oct 24, 2026. Severity score computed from the published CVSS vector.