VulnerabilityRUSTSEC-2026-0330 · libcrux-kem
RUSTSEC-2026-0330: Hybrid Encapsulation from Seed Panics on Short Seed
Short answerA security vulnerability in the libcrux-kem crate: Hybrid Encapsulation from Seed Panics on Short Seed. No severity score was published. Fixed in 0.0.10: update to a fixed version.
| Crate | libcrux-kem |
|---|---|
| Type | Vulnerability |
| Affected versions | Before 0.0.10. |
| Fixed in | 0.0.10 |
| Severity | not scored CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| Published | 2026-09-28 |
| Last changed | 2026-10-07 |
| Also known as | none |
| Affected functions | libcrux_kem::PublicKey::encapsulate_derand |
What to do
- See which version you have:
cargo tree -i libcrux-kem(it also shows which of your dependencies pulls it in). - Update within your version requirement:
cargo update -p libcrux-kem. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for examplelibcrux-kem = "0.0.10") or update the dependency that pulls it in. - Check again with
cargo audit, or paste your Cargo.lock into our Cargo.toml checker.
Details from the advisory
For a hybrid KEM public key of type PublicKey::WingKemDraft06 or PublicKey::X25519MlKem768Draft06, the PublicKey::encapsulate_derand function would panic in an indexing operation on a seed input of length shorter than 32 bytes.
Impact
Applications encapsulating with an attacker controlled seed value could be made to panic. Since the encapsulation seed should be considered a secret of the encapsulating party for the KEM to remain secure, an application should never take the seed value from a potentially attacker controlled source.
Mitigation
With release of version 0.0.10 of libcrux-kem this bug has been fixed and the serialization functions return InvalidPrivateKey and InvalidPublicKey errors on invalid input buffer lengths.
We recommend users upgrade to libcrux-kem version 0.0.10.
References
- Package: crates.io/crates/libcrux-kem
- Advisory: rustsec.org/advisories/RUSTSEC-2026-0330.html
- Web: github.com/celabshq/libcrux/pull/1595
From the RustSec Advisory Database (CC0-1.0) via the OSV export, downloaded Oct 24, 2026. Severity score computed from the published CVSS vector.
Other advisories for libcrux-kem
Up next
Same cratelibcrux-kem: security historyEvery advisory for this crate, and whether it is safe to use today.Read it next →Did this answer your question?