Timing Side-Channel in SM2 Signature Generation
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.
CVE-2026-77696
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-77696
OpenSSL
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "OpenSSL",
"product": "OpenSSL",
"versions": [
{
"status": "affected",
"version": "4.0.0",
"lessThan": "4.0.3",
"versionType": "semver"
},
{
"status": "affected",
"version": "3.6.0",
"lessThan": "3.6.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "3.5.0",
"lessThan": "3.5.9",
"versionType": "semver"
},
{
"status": "affected",
"version": "3.4.0",
"lessThan": "3.4.8",
"versionType": "semver"
},
{
"status": "affected",
"version": "3.0.0",
"lessThan": "3.0.23",
"versionType": "semver"
},
{
"status": "affected",
"version": "1.1.1",
"lessThan": "1.1.1zj",
"versionType": "custom"
}
],
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-77696
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #3834 · Revision 1
- Added to Heist Feed
- Publisher date