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CVE PROGRAM SOURCE RECORD3.7 Low

CVE-2026-77696

Timing Side-Channel in SM2 Signature Generation

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Status
Published
Published
Updated
Assigning organization
openssl

Description

Issue summary: SM2 signature generation uses non-constant-time arithmetic on secret values, forming a timing side-channel. Impact summary: An attacker able to measure SM2 signing times may learn information about the per-signature secret nonce, which over many signatures can, via a lattice / Hidden Number Problem attack, lead to recovery of the private key. CWE: CWE-208: Observable Timing Discrepancy Description: SM2 signature generation computes the signature value using variable-time BIGNUM operations on the secret nonce and the private key, so the time taken to produce an SM2 signature depends on these secret values, forming a timing side-channel. Applications performing SM2 signature generation are affected on all platforms. FIPS Impact: no SM2 is not a FIPS algorithm.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

OpenSSL OpenSSL

Default version status: unaffected

  • 4.0.0 to < 4.0.3affected
  • 3.6.0 to < 3.6.5affected
  • 3.5.0 to < 3.5.9affected
  • 3.4.0 to < 3.4.8affected
  • 3.0.0 to < 3.0.23affected
  • 1.1.1 to < 1.1.1zjaffected

References