3.7

CVE-2026-77696

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
OpenSSL ≫ OpenSSL Version >= 1.1.1 < 1.1.1zj
OpenSSL ≫ OpenSSL Version >= 3.0.0 < 3.0.23
OpenSSL ≫ OpenSSL Version >= 3.4.0 < 3.4.8
OpenSSL ≫ OpenSSL Version >= 3.5.0 < 3.5.9
OpenSSL ≫ OpenSSL Version >= 3.6.0 < 3.6.5
OpenSSL ≫ OpenSSL Version >= 4.0.0 < 4.0.3
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.24% 0.14
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
CISA-ADP 3.7 2.2 1.4
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
CWE-208 Observable Timing Discrepancy

Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.

https://openssl-library.org/news/secadv/20260929.txt
Vendor Advisory
https://github.com/openssl/openssl/commit/1c4aed808a7aea32d2d013049c2e0d9fef164fc9
Patch
https://github.com/openssl/openssl/commit/20b20628d39b2dcc4677194bd68c7c060fa598cb
Patch
https://github.com/openssl/openssl/commit/419f5cb519721dceed393dbc524d79e487c72e64
Patch
https://github.com/openssl/openssl/commit/6b90445a56b99a328ac1feba058abf976504f440
Patch