CVE-2026-50733: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-j39p-jf99-v5w8
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CVSS 8.8
CWE-95
Published
Advisory Summary

CVE-2026-50733 is a HIGH (CVSS 8.8) security vulnerability vulnerability (CWE-95: Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes code syntax before using the input in a dynamic evaluation call (e.g. "eval").. Remediation is available in the latest vendor maintenance releases.

CVE-2026-50733 at a Glance

CVE Identifier CVE-2026-50733
GHSA Identifier GHSA-j39p-jf99-v5w8
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-95: Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.8

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:R/S:U/C:H/I:H/A:H).

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

How to Fix CVE-2026-50733

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

Verify Direct and Transitive Dependencies

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

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-50733, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

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

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-95: Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection'), where the product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes code syntax before using the input in a dynamic evaluation call (e.g. "eval"). In Software, 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

Markdown Preview Enhanced before 0.8.28 parses WaveDrom diagrams by evaluating untrusted markdown content with eval(), allowing arbitrary JavaScript execution. The flaw affects every render path - the live preview (window.eval) and presentation mode plus HTML export (the bundled WaveDrom.ProcessAll()/eva() helpers) - and can also be triggered through a <script type="WaveDrom"> element injected via raw HTML in markdown. When a victim previews or exports a crafted markdown document, an attacker can execute arbitrary code, leading to arbitrary file write. Fixed in 0.8.28 by parsing with JSON5.parse() and sanitizing WaveDrom data scripts to inert strict JSON.

References

NVD — CVE-2026-50733 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-50733
Software Source Repository REPOSITORY
https://github.com/shd101wyy/vscode-markdown-preview-enhanced/issues/2315
Software Release RELEASE
https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.28
www.vulncheck.com/advisories/markdown... WEB
https://www.vulncheck.com/advisories/markdown-preview-enhanced-arbitrary-code-execution-via-wavedrom-eval

Frequently Asked Questions

What is CVE-2026-50733?
CVE-2026-50733 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-95: Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-50733?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-50733?
CVE-2026-50733 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-50733?
CVE-2026-50733 is classified under CWE-95: Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection') (The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes code syntax before using the input in a dynamic evaluation call (e.g. "eval").).
How can I check Maven dependencies for CVE-2026-50733?
Run the dependency tree command: 'mvn dependency:tree'. 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-j39p-jf99-v5w8",
  "modified" : "2026-06-05T18:31:41Z",
  "published" : "2026-06-05T18:31:41Z",
  "aliases" : [ "CVE-2026-50733" ],
  "details" : "Markdown Preview Enhanced before 0.8.28 parses WaveDrom diagrams by evaluating untrusted markdown content with eval(), allowing arbitrary JavaScript execution. The flaw affects every render path - the live preview (window.eval) and presentation mode plus HTML export (the bundled WaveDrom.ProcessAll()/eva() helpers) - and can also be triggered through a <script type=\"WaveDrom\"> element injected via raw HTML in markdown. When a victim previews or exports a crafted markdown document, an attacker can execute arbitrary code, leading to arbitrary file write. Fixed in 0.8.28 by parsing with JSON5.parse() and sanitizing WaveDrom data scripts to inert strict JSON.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-50733"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/shd101wyy/vscode-markdown-preview-enhanced/issues/2315"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/shd101wyy/vscode-markdown-preview-enhanced/releases/tag/0.8.28"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/markdown-preview-enhanced-arbitrary-code-execution-via-wavedrom-eval"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-95" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-06-05T18:17:34Z"
  }
}