CVE-2026-4258: Sjcl Sjcl Is Missing Point-on-curve Validation Vulnerability

HIGH
Advisory Identifier: GHSA-2w8x-224x-785m
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CVSS 7.5
CWE-325 CWE-347
Published
Advisory Summary

CVE-2026-4258 is a HIGH (CVSS 7.5) sjcl is missing point-on-curve validation vulnerability (CWE-325: Missing Cryptographic Step) affecting Sjcl libraries in the npm ecosystem. The issue involves sjcl is missing point-on-curve validation in sjcl.ecc.basickey.publickey. Remediation is available by upgrading affected packages to version 1.0.9.

CVE-2026-4258 at a Glance

CVE Identifier CVE-2026-4258
GHSA Identifier GHSA-2w8x-224x-785m
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-325: Missing Cryptographic Step
Affected Product Sjcl
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-4258

To remediate this vulnerability, upgrade all affected Sjcl dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

sjcl fixed: 1.0.9 
npm install sjcl@1.0.9
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls sjcl

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-4258, inspect your project dependencies using npm:

npm ls sjcl

Analyze the terminal output to locate any version of Sjcl in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.9), your application is affected.

Note: The npm ls sjcl command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-325: Missing Cryptographic Step, where the product does not implement a required step in a cryptographic algorithm, resulting in weaker encryption than advertised by the algorithm. In Sjcl, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

All versions of the package sjcl are vulnerable to Improper Verification of Cryptographic Signature due to missing point-on-curve validation in sjcl.ecc.basicKey.publicKey(). An attacker can recover a victim's ECDH private key by sending crafted off-curve public keys and observing ECDH outputs. The dhJavaEc() function directly returns the raw x-coordinate of the scalar multiplication result (no hashing), providing a plaintext oracle without requiring any decryption feedback.

CVE-2026-4258 Affected Sjcl Versions

1 component(s)
Fixed Versions:
1.0.9
Product / Package Ecosystem Affected Versions Fixed Version
sjcl
npm/sjcl
npm
< 1.0.9
1.0.9

References

NVD — CVE-2026-4258 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-4258
Security Fix Commit FIX COMMIT
https://github.com/bitwiseshiftleft/sjcl/commit/ee307459972442a17beebc29dc331fffd8aff796
Sjcl Source Repository REPOSITORY
https://gist.github.com/Kr0emer/2560f98edb10b0b34f2438cd63913c47
Sjcl Source Repository REPOSITORY
https://github.com/bitwiseshiftleft/sjcl
Sjcl Source Repository REPOSITORY
https://github.com/bitwiseshiftleft/sjcl/blob/master/core/ecc.js#L454-L461
Sjcl Security Information SECURITY
https://security.snyk.io/vuln/SNYK-JS-SJCL-15369617

Frequently Asked Questions

What is CVE-2026-4258?
CVE-2026-4258 is a security vulnerability in Sjcl involving sjcl is missing point-on-curve validation in sjcl.ecc.basicKey.publicKey under CWE-325: Missing Cryptographic Step.
Which Sjcl versions are affected?
Affected versions include releases prior to 1.0.9 across affected packages: sjcl.
What version fixes CVE-2026-4258?
Upgrading to 1.0.9 (or the latest patched release for your respective branch) resolves the vulnerability.
Is sjcl affected?
Yes, sjcl is affected in releases prior to 1.0.9. Upgrade your dependency to 1.0.9 or later.
What is the CVSS score of CVE-2026-4258?
CVE-2026-4258 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-4258?
CVE-2026-4258 is classified under CWE-325: Missing Cryptographic Step (The product does not implement a required step in a cryptographic algorithm, resulting in weaker encryption than advertised by the algorithm.).
How can I check npm dependencies for CVE-2026-4258?
Run the dependency tree command: 'npm ls sjcl'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-2w8x-224x-785m",
  "modified" : "2026-03-25T14:36:28Z",
  "published" : "2026-03-17T06:31:32Z",
  "aliases" : [ "CVE-2026-4258" ],
  "summary" : "sjcl is missing point-on-curve validation in sjcl.ecc.basicKey.publicKey",
  "details" : "All versions of the package sjcl are vulnerable to Improper Verification of Cryptographic Signature due to missing point-on-curve validation in sjcl.ecc.basicKey.publicKey(). An attacker can recover a victim's ECDH private key by sending crafted off-curve public keys and observing ECDH outputs. The dhJavaEc() function directly returns the raw x-coordinate of the scalar multiplication result (no hashing), providing a plaintext oracle without requiring any decryption feedback.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS: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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "sjcl"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.0.9"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.0.8"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-4258"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/bitwiseshiftleft/sjcl/commit/ee307459972442a17beebc29dc331fffd8aff796"
  }, {
    "type" : "WEB",
    "url" : "https://gist.github.com/Kr0emer/2560f98edb10b0b34f2438cd63913c47"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/bitwiseshiftleft/sjcl"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/bitwiseshiftleft/sjcl/blob/master/core/ecc.js#L454-L461"
  }, {
    "type" : "WEB",
    "url" : "https://security.snyk.io/vuln/SNYK-JS-SJCL-15369617"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-325", "CWE-347" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-18T16:10:06Z",
    "nvd_published_at" : "2026-03-17T06:16:18Z"
  }
}