OpenSSLに脆弱性（CVE-2026-54872）
概要
OpenSSLに脆弱性が確認されました。
バージョン 1.0.2 以上 1.0.2zs 未満、1.1.1 以上 1.1.1zj 未満、3.0.0 以上 3.0.23 未満、3.4.0 以上 3.4.8 未満、3.5.0 以上 3.5.9 未満、3.6.0 以上 3.6.5 未満 ほか1範囲に影響があります。
修正版 1.0.2zs / 1.1.1zj / 3.0.23 / 3.4.8 / 3.5.9 / 3.6.5 / 4.0.3 への更新が推奨されます。
脆弱性の基本情報
| 脆弱性ID | CVE-2026-54872 |
|---|---|
| 脆弱性の種類 | CWE-208 |
| 危険度 | 低 |
| CVSSスコア |
3.7（CVSS v3.1） CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |
| 公開日 | 2026年9月29日 |
| 更新日 | 2026年10月8日 |
影響を受ける製品
| 製品 | 影響を受けるバージョン | 修正版 | 出典 |
|---|---|---|---|
| OpenSSL |
1.0.2 以上 1.0.2zs 未満、1.1.1 以上 1.1.1zj 未満、3.0.0 以上 3.0.23 未満、3.4.0 以上 3.4.8 未満、3.5.0 以上 3.5.9 未満、3.6.0 以上 3.6.5 未満 ほか1範囲 | 1.0.2zs / 1.1.1zj / 3.0.23 / 3.4.8 / 3.5.9 / 3.6.5 / 4.0.3 | NVD（National Vulnerability Database / NIST） |
推奨対応
- OpenSSLを、ご利用中の系列に対応する修正版（1.0.2zs / 1.1.1zj / 3.0.23 / 3.4.8 / 3.5.9 / 3.6.5 / 4.0.3）またはそれ以降の公式最新版へ更新してください。
- OpenSSLを OS・ディストリビューションのパッケージで利用している場合は、提供元の公式セキュリティ更新が適用されているかを確認してください（独自に修正が取り込まれている場合があります）。
情報元の原文
NVD（National Vulnerability Database / NIST）
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.
利用条件：米国政府の著作物（パブリックドメイン）・原文のまま掲載
Copyright 1999-2026 The MITRE Corporation
CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.
CVE List（CVE Program）
Timing Side-Channel in Scalar Multiplication for Non-NIST EC Curves
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.
利用条件：CVE の利用条件（CVE Terms of Use）・原文のまま掲載
Copyright 1999-2026 The MITRE Corporation
CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.
情報元
- NVD（National Vulnerability Database / NIST）
https://nvd.nist.gov/vuln/detail/CVE-2026-54872 - CVE List（CVE Program）
https://www.cve.org/CVERecord?id=CVE-2026-54872