CVE-2026-22698
Severity CVSS v4.0:
HIGH
Type:
CWE-331
Insufficient Entropy
Publication date:
10/01/2026
Last modified:
10/01/2026
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.
Impact
Base Score 4.0
8.70
Severity 4.0
HIGH
References to Advisories, Solutions, and Tools
- https://crates.io/crates/sm2/0.14.0-pre.0
- https://crates.io/crates/sm2/0.14.0-rc.0
- https://github.com/RustCrypto/elliptic-curves/commit/4781762f23ff22ab34763410f648128055c93731
- https://github.com/RustCrypto/elliptic-curves/commit/e4f77788130d065d760e57fb109370827110a525
- https://github.com/RustCrypto/elliptic-curves/pull/1600
- https://github.com/RustCrypto/elliptic-curves/security/advisories/GHSA-w3g8-fp6j-wvqw