Copyright © 2012 Red Hat, Inc. All rights reserved.
Moderate
2026-09-29T15:32:15
openssl: OpenSSL: Private key recovery via timing side-channel in generic elliptic curve operations
5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CWE-208
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.
A flaw was found in OpenSSL. A timing side-channel vulnerability in generic elliptic curve scalar multiplication allows an attacker to recover private cryptographic keys. When performing signature operations, such as the Elliptic Curve Digital Signature Algorithm (ECDSA) or SM2, using curves without dedicated constant-time implementations, variations in processing time leak information about the per-signature secret value. By measuring the duration of numerous signing operations, an attacker can analyze these timing differences to reconstruct the private signing key.
This issue is rated Moderate because generic elliptic-curve scalar multiplication used for ECDSA/SM2 on non-NIST curves can leak timing information about the secret nonce, which with many measurements may enable private-key recovery via lattice/HNP techniques. NIST P-256/P-384/P-521 dedicated paths are not affected, and FIPS-approved NIST curves in the FIPS provider are not affected. Attack complexity is high due to the volume of precise timing samples required.
Prefer NIST curves with dedicated constant-time implementations (P-256, P-384, P-521) for ECDSA. Avoid Brainpool and other generic prime curves for high-value signing where practical.
Red Hat Hardened Images
2026-09-30T00:00:00Z
RHSA-2026:74162
openssl-main-3.5.9-0.1.hum1
Red Hat Hardened Images
2026-09-30T00:00:00Z
RHSA-2026:74166
openssl3-main-3.5.9-0.1.hum1
Red Hat Developer Hub 1
Fix deferred
rhdh/rhdh-hub-rhel9
Red Hat Enterprise Linux 10
Fix deferred
edk2
Red Hat Enterprise Linux 10
Fix deferred
openssl
Red Hat Enterprise Linux 10
Fix deferred
shim
Red Hat Enterprise Linux 10
Fix deferred
shim-unsigned-aarch64
Red Hat Enterprise Linux 10
Fix deferred
shim-unsigned-x64
Red Hat Enterprise Linux 6
Out of support scope
openssl
Red Hat Enterprise Linux 7
Fix deferred
openssl
Red Hat Enterprise Linux 7
Fix deferred
ovmf
Red Hat Enterprise Linux 7
Fix deferred
shim-signed
Red Hat Enterprise Linux 8
Fix deferred
compat-openssl10
Red Hat Enterprise Linux 8
Fix deferred
edk2
Red Hat Enterprise Linux 8
Fix deferred
mingw-openssl
Red Hat Enterprise Linux 8
Fix deferred
openssl
Red Hat Enterprise Linux 8
Fix deferred
shim
Red Hat Enterprise Linux 8
Fix deferred
shim-unsigned-aarch64
Red Hat Enterprise Linux 8
Fix deferred
shim-unsigned-x64
Red Hat Enterprise Linux 9
Fix deferred
compat-openssl11
Red Hat Enterprise Linux 9
Under investigation
edk2
Red Hat Enterprise Linux 9
Affected
openssl
Red Hat Enterprise Linux 9
Fix deferred
shim
Red Hat Enterprise Linux 9
Fix deferred
shim-unsigned-aarch64
Red Hat Enterprise Linux 9
Fix deferred
shim-unsigned-x64
Red Hat Hardened Images
Not affected
unbound
Red Hat JBoss Core Services
Fix deferred
jbcs-httpd24-openssl
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-ai-gateway-operator-rhel9
Red Hat OpenShift AI (RHOAI)
Under investigation
rhoai/odh-core-bff-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-dashboard-operator-rhel9
Red Hat OpenShift AI (RHOAI)
Under investigation
rhoai/odh-dashboard-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-data-science-pipelines-operator-controller-rhel9
Red Hat OpenShift AI (RHOAI)
Under investigation
rhoai/odh-kf-notebook-controller-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-kserve-controller-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-kserve-llmisvc-controller-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-kserve-module-operator-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-kuberay-operator-controller-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-kube-rbac-proxy-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-llama-stack-k8s-operator-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-maas-controller-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-mlflow-operator-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-mlflow-rhel9
Red Hat OpenShift AI (RHOAI)
Under investigation
rhoai/odh-mod-arch-agent-ops-rhel9
Red Hat OpenShift AI (RHOAI)
Under investigation
rhoai/odh-mod-arch-automl-rhel9
Red Hat OpenShift AI (RHOAI)
Under investigation
rhoai/odh-mod-arch-autorag-rhel9
Red Hat OpenShift AI (RHOAI)
Under investigation
rhoai/odh-mod-arch-eval-hub-rhel9
Red Hat OpenShift AI (RHOAI)
Under investigation
rhoai/odh-mod-arch-gen-ai-rhel9
Red Hat OpenShift AI (RHOAI)
Under investigation
rhoai/odh-mod-arch-maas-rhel9
Red Hat OpenShift AI (RHOAI)
Under investigation
rhoai/odh-mod-arch-mlflow-rhel9
Red Hat OpenShift AI (RHOAI)
Under investigation
rhoai/odh-mod-arch-model-registry-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-model-controller-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-model-registry-operator-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-model-serving-api-rhel9
Red Hat OpenShift AI (RHOAI)
Under investigation
rhoai/odh-notebook-controller-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-ogx-k8s-operator-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-ogx-module-operator-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-training-operator-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-trustyai-service-operator-rhel9
Red Hat OpenShift AI (RHOAI)
Not affected
rhoai/odh-workbenches-operator-rhel9
Red Hat OpenShift Container Platform 4
Fix deferred
openshift/ose-rhel-coreos-8
Red Hat OpenShift Container Platform 4
Fix deferred
openshift/ose-rhel-coreos-9
Red Hat OpenShift Container Platform 5
Fix deferred
openshift/ose-rhel-coreos-9
Red Hat Satellite 6
Fix deferred
openvox-agent
Red Hat Satellite 6
Fix deferred
puppet-agent
https://www.cve.org/CVERecord?id=CVE-2026-54872
https://nvd.nist.gov/vuln/detail/CVE-2026-54872
https://github.com/openssl/openssl/commit/1a5bee8dc57430a2be69cd1ffe7fec6a62f4f179
https://github.com/openssl/openssl/commit/3f7e1363dccec6f7732bb9e9fa471bb6e4aa68cb
https://github.com/openssl/openssl/commit/7d83bc7764999dfd91b83b4f0815b45390422afd
https://github.com/openssl/openssl/commit/8166827a78aad164a07aa86dea2b425403ced471
https://openssl-library.org/news/secadv/20260929.txt