Skip to content

CVE-2026-54872 on Cyberus Linux 26.05

Aliases: CVE-2026-54872

Packages: openssl_3_6

Status: Resolved

Advisory Information

Issue summary: The generic elliptic-curve scalar multiplication used for ECDSA and SM2 signature operations with curves that do not have a dedicated implementation leaks information about the secret nonce through timing.

Impact summary: An attacker able to measure 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: The generic elliptic-curve scalar multiplication used for curves that do not have a dedicated constant-time implementation pads the secret scalar with non-constant-time BIGNUM operations, so the time taken depends on the value of the secret scalar derived from the ECDSA and SM2 nonce.

The leak is very small; observing it requires a large number of measurements. The effect is largest for curves whose group order lies on a machine-word boundary, such as brainpoolP384r1.

Applications using ECDSA signing over the Brainpool and other generic prime curves, and SM2 signing on platforms that use the generic implementation, are vulnerable to this issue.

The NIST curves P-256, P-384 and P-521 use dedicated constant-time implementations and are not affected.

FIPS Impact: no The FIPS modules are not affected: the approved NIST curves used in the FIPS provider have dedicated constant-time implementations and do not use the affected code path.

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”