The vulnerability identified as CVE-2026-22698 affects RustCrypto's elliptic-curves library, specifically versions 0.14.0-pre.0 and 0.14.0-rc.0. The flaw lies in the SM2 Public Key Encryption (PKE) implementation where the ephemeral nonce k, critical for ensuring the security of each encryption operation, is generated with insufficient entropy. This is caused by a unit mismatch error in the nonce generation function, which requests only 32 bits of randomness instead of the intended 256 bits. As a result, the effective security level of the encryption is drastically reduced from the expected 128-bit strength to roughly 16 bits, making brute-force or cryptanalytic recovery of the nonce feasible with modest computational effort. Once the nonce k is recovered, an attacker can decrypt any ciphertext encrypted under the same public key without needing the private key. The vulnerability requires no privileges, no authentication, and no user interaction, and can be exploited remotely by an attacker with access to the ciphertext and public key. This weakness compromises the confidentiality of encrypted communications or data protected by the affected SM2 implementation. The issue has been addressed and patched in subsequent versions of the library, with the fix committed in e4f7778. No known exploits have been reported in the wild to date, but the vulnerability's nature and severity make it a critical concern for any system relying on these specific RustCrypto versions for elliptic curve cryptography.

For European organizations, the impact of this vulnerability is significant, particularly for those utilizing RustCrypto's elliptic-curves library in their cryptographic stacks, especially where SM2 encryption is employed. The compromised nonce entropy allows attackers to decrypt sensitive communications or data, undermining confidentiality guarantees. This can lead to exposure of personal data, intellectual property, or sensitive business information, potentially violating GDPR and other data protection regulations. Industries such as finance, telecommunications, government, and critical infrastructure that rely on strong ECC-based encryption are at heightened risk. The ease of exploitation and lack of required authentication mean attackers can remotely compromise encrypted data without insider access. This vulnerability could also erode trust in cryptographic implementations and cause operational disruptions if exploited. Although no active exploits are known, the vulnerability's presence in widely used cryptographic libraries necessitates urgent remediation to prevent future attacks.

European organizations should immediately identify and inventory all systems and applications using RustCrypto elliptic-curves versions 0.14.0-pre.0 or 0.14.0-rc.0, focusing on those employing SM2 encryption. The primary mitigation is to upgrade to the latest patched version of the RustCrypto elliptic-curves library where the nonce generation bug is fixed (commit e4f7778 or later). If upgrading is not immediately feasible, organizations should consider disabling or replacing SM2 encryption with alternative, secure cryptographic algorithms until patched versions can be deployed. Conduct thorough code and dependency audits to detect indirect usage of vulnerable versions via third-party libraries. Implement network monitoring to detect unusual cryptographic traffic patterns that may indicate exploitation attempts. Additionally, enforce strict cryptographic policy management to prevent deployment of vulnerable library versions in production. Finally, ensure that cryptographic keys and encrypted data potentially exposed by this vulnerability are rotated or re-encrypted after patching to mitigate risks from past exposures.