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CVE-2026-77696 on Cyberus Linux 26.05

Aliases: CVE-2026-77696

Packages: openssl_3_6

Status: Resolved

Advisory Information

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.

Updates

2026-10-09 02:48 CEST

Metadata changes:

  • Status for package openssl_3_6: “Resolved” (257cd5b258336d6254b2bf4b5c12156b7b8f8821)

2026-10-05 16:30 CEST

Metadata changes:

  • Status for package openssl_3_6: “In Progress” (257cd5b258336d6254b2bf4b5c12156b7b8f8821)

(Amended on: 2026-10-05 16:31 CEST)

2026-10-05 16:28 CEST

Metadata changes:

  • Status for package openssl_3: “Package not supported” (1f5405d51c08776fb35a8dd8ecc33da81cb52f42)

Comment:

OpenSSL 3.0 has reached EOL status and will not receive further security updates.

2026-10-05 16:27 CEST

Metadata changes:

  • Status for package openssl_3_5: “Resolved” (1f5405d51c08776fb35a8dd8ecc33da81cb52f42)

2026-10-05 16:27 CEST

Metadata changes:

  • Status for package openssl_4_0: “Resolved” (1f5405d51c08776fb35a8dd8ecc33da81cb52f42)

2026-10-01 01:19 CEST

Metadata changes:

  • Status for package openssl_3_5: “In Progress” (1f5405d51c08776fb35a8dd8ecc33da81cb52f42)

2026-10-01 01:18 CEST

Metadata changes:

  • Status for package openssl_4_0: “In Progress” (77f391603c7ef9448f3b3cb5d9aa3b01783836d6)

2026-09-30 09:55 CEST

Metadata changes:

  • Status for package openssl_3_5: “In Progress” (1f5405d51c08776fb35a8dd8ecc33da81cb52f42)

2026-09-29 19:52 CEST

Metadata changes:

  • Status for package openssl_3: “Plausible”
  • Status for package openssl_3_5: “Plausible”
  • Status for package openssl_3_6: “Plausible”
  • Status for package openssl_4_0: “Plausible”

(Amended on: 2026-09-29 19:53 CEST)

2026-09-29 19:24 CEST

Metadata changes:

  • Status for package openssl_3: “New”
  • Status for package openssl_3_5: “New”
  • Status for package openssl_3_6: “New”
  • Status for package openssl_4_0: “New”