Open Source Software
CVE-2020-1026 — MSR JavaScript Cryptography Library Security Feature Bypass Vulnerability
Executive Summary
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. In addition, an internal review resulted in other improvements to prevent rare failures in ECDH and ECDSA when using the NUMS curves.
Overview
9.8
CVSS CRITICAL
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
EPSS Score
0.02541
probability of exploitation in the next 30 days
0.82934 percentile - updated 2026-06-21
View on FIRST.org
Affected Products
1 affected product
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Microsoft Research JavaScript Cryptography Library V1.4 | Release Notes (Security Update) |
Important | Security Feature Bypass | Maybe |
Patches
1 patch
| Article | Type | Restart |
|---|---|---|
Release Notes |
Security Update | Maybe |
Known Exploits
No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.
Acknowledgments
References
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