CVE-2026-54875

A flaw was found in OpenSSL. The optimized scalar point multiplication used for SM2 cryptographic operations on ARM64 and RISC-V architectures does not execute in constant time. An attacker capable of measuring execution times or observing processor cache-access patterns can exploit this side channel during decryption or digital signature generation. This vulnerability allows the attacker to deduce sensitive private keys or signature nonces, leading to information disclosure.

This issue is rated Moderate because the optimized SM2 scalar multiplication on ARM64 and RISC-V is not constant-time, so a local attacker who can measure timing or cache behavior of SM2 signing/decryption may learn information about the secret scalar. SM2 is not a FIPS algorithm and the path is outside the FIPS module.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

If SM2 is not required, disable or avoid SM2 keys/algorithms in the application configuration. On aarch64/riscv64 hosts that must use SM2, restrict local access to processes performing SM2 private-key operations.