Vulnerability · Published Jan 10, 2026 · Assigned by GitHub_M
CVE-2026-22698RustCrypto SM2-PKE has 32-bit Biased Nonce Vulnerability
High 8.7
In plain English
A high-severity security flaw in elliptic-curves from RustCrypto. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities).
Official 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 (as reported)
| Vendor | Product | Versions |
|---|---|---|
| RustCrypto | elliptic-curves | = 0.14.0-pre.0= 0.14.0-rc.0 |
Weakness: CWE-331 · Vector: 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
References
- https://github.com/RustCrypto/elliptic-curves/security/advisories/GHSA-w3g8-fp6j-wvqw x_refsource_CONFIRM
- https://github.com/RustCrypto/elliptic-curves/pull/1600 x_refsource_MISC
- https://github.com/RustCrypto/elliptic-curves/commit/4781762f23ff22ab34763410f648128055c93731 x_refsource_MISC
- https://github.com/RustCrypto/elliptic-curves/commit/e4f77788130d065d760e57fb109370827110a525 x_refsource_MISC
- https://crates.io/crates/sm2/0.14.0-pre.0 x_refsource_MISC
- https://crates.io/crates/sm2/0.14.0-rc.0 x_refsource_MISC