RUSTSEC-2026-0387

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Source

https://rustsec.org/advisories/RUSTSEC-2026-0387

Import Source

https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0387.json

JSON Data

https://api.osv.dev/v1/vulns/RUSTSEC-2026-0387

Published

2026-10-23T12:00:00Z

Modified

2026-10-24T03:45:02Z

Summary

Multiple timing variability issues in operations intended to be constant-time

Details

Summary

Several operations intended to be constant-time could execute secret-dependent branches, depending on the compiler and target CPU. These include subtraction, zero counting, division, and Montgomery multiplication.

Additionally, UintRef equality could terminate at the first unequal limb, and BoxedMontyForm::invert branched on whether an inverse exists.

Impact

Applications using affected operations on secret integers may leak information through timing or microarchitectural side channels. This includes information about intermediate arithmetic values, matching limbs, and invertibility.

Such leakage could potentially enable recovery of cryptographic secrets. Practical exploitability depends on the downstream algorithm, compiler, target CPU, and an attacker's ability to observe the side channel.

Resolution

Upgrade to v0.7.6, which removes the identified branches, updates ctutils to include its constant-time fixes, and adds BINSEC-based regression checks using cargo checkct for arithmetic on multiple targets.

Database specific

{
    "license":  "CC-BY-4.0"
}

References

Affected packages

crates.io / crypto-bigint

Package

Name: crypto-bigint; View open source insights on deps.dev
Purl: pkg:cargo/crypto-bigint

Affected ranges

Type: SEMVER
Events: Introduced

0.0.0-0

Fixed

0.7.6

Ecosystem specific

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