CVE-2026-4258Public exploitNetwork attack vector

ECDH private-key recovery via unchecked curve points

Published Mar 17, 2026 · Updated Mar 17, 2026

Invalid-curve handling in Stanford Javascript Crypto Library before 1.0.9 allows remote attackers to recover ECDH private keys. The sjcl.ecc.basicKey.publicKey constructor accepts an sjcl.ecc.point object without calling isValid(), and dhJavaEc() exposes the raw x-coordinate of scalar multiplication. The attack requires an application to pass attacker-controlled point objects into ECDH and return deterministic ECDH output; repeated off-curve queries disclose the private scalar.

CVSS severity7.5
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Invalid-curve handling in Stanford Javascript Crypto Library before 1.0.9 allows remote attackers to recover ECDH private keys. The sjcl.ecc.basicKey.publicKey constructor accepts an sjcl.ecc.point object without calling isValid(), and dhJavaEc() exposes the raw x-coordinate of scalar multiplication. The attack requires an application to pass attacker-controlled point objects into ECDH and return deterministic ECDH output; repeated off-curve queries disclose the private scalar.

The record

CVE
CVE-2026-4258
Published
Mar 17, 2026
Updated
Mar 17, 2026
Vendor
Stanford University
Product
Stanford Javascript Crypto Library
Classifications
CWE-347, CWE-325
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=0 <*

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Stanford University · Stanford Javascript Crypto Libraryversion=0 <*

Published CVSS scores

7.7SnykCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P
7.5SnykCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
CWE-325Missing Cryptographic Step

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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