Back

HIGH

RustCrypto SM2-PKE has 32-bit Biased Nonce Vulnerability

Published Jan 10, 2026

Description

RustCrypto: Elliptic Curves is general purpose Elliptic Curve Cryptography (ECC) support, including types and traits for representing various elliptic curve forms, scalars, points, and public/secret keys composed thereof. In versions 0.14.0-pre.0 and 0.14.0-rc.0, a critical vulnerability exists in the SM2 Public Key Encryption (PKE) implementation where the ephemeral nonce k is generated with severely reduced entropy. A unit mismatch error causes the nonce generation function to request only 32 bits of randomness instead of the expected 256 bits. This reduces the security of the encryption from a 128-bit level to a trivial 16-bit level, allowing a practical attack to recover the nonce k and decrypt any ciphertext given only the public key and ciphertext. This issue has been patched via commit e4f7778.

Affected products

Remediation

No remediation recorded yet.

Weaknesses (1)

References (9)

Change history (0)

No recorded changes yet.

Sources

CVE.org / MITRE

Status PUBLISHED
Assigner GitHub_M
Published Jan 10, 2026
Updated Jan 12, 2026
Reserved Jan 8, 2026

CISA Vulnrichment

Updated Jan 12, 2026

NVD

Status Analyzed
Modified Jun 17, 2026

Red Hat

No data

ENISA EUVD

Assigner GitHub_M
Published Jan 10, 2026
Updated Jan 12, 2026