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CVE-2020-1026

CRITICAL

A Security Feature Bypass vulnerability exists in the MSR JavaScript Cryptography Library that is caused by multiple bugs in the library’s Elliptic Curve Cryptography (ECC) implementation.An attacker could potentially abuse these bugs to learn information about a server’s private ECC key (a key leakage attack) or craft an invalid ECDSA signature that nevertheless passes as valid.The security update addresses the vulnerability by fixing the bugs disclosed in the ECC implementation, aka 'MSR JavaScript Cryptography Library Security Feature Bypass Vulnerability'.

Published: Apr 15, 2020 Modified: Jun 17, 2026
CWE-200 CWE-347

CVSS Metrics

CVSSv3
Attack Vector: NETWORK Attack Complexity: LOW Privileges Required: NONE User Interaction: NONE Scope: UNCHANGED Confidentiality Impact: HIGH Integrity Impact: HIGH Availability Impact: HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Products (1)

Vendor Product Version
microsoft research_javascript_cryptography_library 1.4

GitHub Security Advisory GHSA-9x9j-836w-8f55

Incorrect Calculation in the MSR JavaScript Cryptography Library

npm msrcrypto < 1.5.8 Fixed: 1.5.8

Risk Scores

CVSS Score 9.8 / 10
EPSS Score 2.54%

Top 16% most likely to be exploited

Threat Score 40 / 100

Data Sources

NVD EPSS GitHub