CVE-2026-87737

Timing Side Channel in NIST Elliptic‑Curve Scalar Multiplication

Published Sep 9, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
Description
An issue was discovered in the mirage-crypto-ec package before 2.4.0 for OCaml. There is a timing side channel for NIST elliptic-curve scalar multiplication: the time required for a lookup can depend on a secret.

Analysis

AI-generated

Technical impact

An analysis of the mirage-crypto-ec package before version 2.4.0 reveals a timing side channel in the implementation of NIST elliptic‑curve scalar multiplication. The execution duration of a lookup operation can vary based on a secret key, allowing an attacker who can measure timing with sufficient precision to infer sensitive values. This weakness could compromise the confidentiality of private keys or other secrets used in cryptographic operations.

Affected Systems

The vulnerability is present in the OCaml mirage-crypto-ec package for all releases prior to 2.4.0. Systems that rely on this library for elliptic‑curve operations, such as secure communication stacks or other cryptographic services written in OCaml, are affected.

Risk and Exploitability

The CVSS score of 5.9 indicates moderate severity. There is no EPSS data, and the vulnerability is not listed in the CISA KEV catalogue. The attack vector is inferred from the nature of the flaw: an adversary would need to observe or influence the timing of scalar multiplication operations, which suggests a local or privileged context unless the service exposes timing data to untrusted parties. The overall risk is moderate, but the potential for key compromise warrants timely remediation.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade mirage-crypto-ec to version 2.4.0 or later where the timing side channel has been mitigated.
  • Configure systems to avoid exposing timing information to hostile observers, such as disabling detailed latency logs or using network padding.
  • If an upgrade is not immediately possible, replace the vulnerable scalar multiplication routine with a constant‑time implementation from a trusted source.
  • Implement monitoring to detect anomalous timing behavior that could indicate an active side‑channel exploitation attempt.

Generated by OpenCVE AI on September 9, 2026 at 11:17 UTC.

Tracking

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Advisories

No advisories available
References
History
Type Values Removed Values Added
First Time appeared Ocaml
Ocaml mirage-crypto-ec
Vendors & Products Ocaml
Ocaml mirage-crypto-ec
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Timing Side Channel in NIST Elliptic‑Curve Scalar Multiplication
Type Values Removed Values Added
Description An issue was discovered in the mirage-crypto-ec package before 2.4.0 for OCaml. There is a timing side channel for NIST elliptic-curve scalar multiplication: the time required for a lookup can depend on a secret.
Weaknesses CWE-208
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N'}

Weaknesses
  • CWE-208

    Observable Timing Discrepancy

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Sep 9, 2026, 1:10 PM
Reserved
Sep 9, 2026, 4:21 AM
Status
Deferred
Published
Sep 9, 2026, 5:18 AM
Modified
Sep 9, 2026, 4:04 PM