Skip to content
Fencer Vulns
critical 9.8

CVE-2020-1026 json

Incorrect Calculation in the MSR JavaScript Cryptography Library

published 2020-04-15 6 y ago modified 2026-06-17 4 mo ago also GHSA-9x9j-836w-8f55 , EUVD-2022-0551

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.6%
EPSS 2.6% chance of exploitation in 30 days, percentile 85%
public exploits
0
none known

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, aka 'MSR JavaScript Cryptography Library Security Feature Bypass Vulnerability'.

Patch / fix

  • npm msrcrypto 1.5.8

Exploit prediction

2.60% chance of exploitation in the next 30 days, higher than 85% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
npm msrcrypto
<1.5.8
1.5.8

Affected products

  • Microsoft Microsoft Research JavaScript Cryptography Library V1.4

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-347 Improper Verification of Cryptographic Signature
  • CWE-682 Incorrect Calculation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.