CVE-2026-22698

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.

Score

CVSS 4.0 8.7 High

Status

Analyzed - security-advisories@github.com

Published

2026-01-10

Last modified

2026-01-12

Weaknesses

CWE-331

Affected products

• Elliptic-curves (Rustcrypto)
• Sm2 Elliptic Curve (Rustcrypto)

References

• 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