CVE 8.7 HIGH

RustCrypto SM2-PKE has 32-bit Biased Nonce Vulnerability_CVE-2026-22698

January 10, 2026 invoker category_cve

8.7 / 10

HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

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.

AI Analysis

A critical vulnerability exists in the SM2 Public Key Encryption (PKE) implementation where the ephemeral nonce k is generated with severely reduced entropy, reducing the security of the encryption from a 128-bit level to a trivial 16-bit level.

Basic Information

ID CVE-2026-22698

Source GitHub_M

Published Jan 10, 2026 at 05:17

Affected Product

Vendor RustCrypto

Product elliptic-curves

Version = 0.14.0-pre.0

Affected Versions RustCrypto elliptic-curves = 0.14.0-pre.0
RustCrypto elliptic-curves = 0.14.0-rc.0

CWE Classification

CWE-331

AI Assessment

AI Score 8.7 / 10

AI Severity High

Vendor RustCrypto

Product elliptic-curves

Version 0.14.0-pre.0, 0.14.0-rc.0

References

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    "published": "2026-01-10T05:17:19.993Z",
    "modified": "2026-01-10T05:17:19.993Z",
    "type": "cve",
    "title": "RustCrypto SM2-PKE has 32-bit Biased Nonce Vulnerability",
    "source": "GitHub_M",
    "references": "https://github.com/RustCrypto/elliptic-curves/security/advisories/GHSA-w3g8-fp6j-wvqw\nhttps://github.com/RustCrypto/elliptic-curves/pull/1600\nhttps://github.com/RustCrypto/elliptic-curves/commit/4781762f23ff22ab34763410f648128055c93731\nhttps://github.com/RustCrypto/elliptic-curves/commit/e4f77788130d065d760e57fb109370827110a525\nhttps://crates.io/crates/sm2/0.14.0-pre.0\nhttps://crates.io/crates/sm2/0.14.0-rc.0",
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