CVE-2026-22698: rustcrypto elliptic-curves Insufficient Entropy

Vulnerability summary

CVE-2026-22698 is a high (CVSS 8.7) Insufficient Entropy vulnerability in rustcrypto elliptic-curves. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 18.7% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 10-01-2026
   PublishedVulnerability first disclosed.
2. 12-01-2026
   Last modifiedVulnerability information updated.

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.

• CWE-331Insufficient EntropyThe product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.