CVE-2026-5802Public exploitNetwork attack vector

Unauthenticated command execution via jar path interpolation

Published Apr 8, 2026 · Updated Apr 8, 2026

OS command injection in Ivan Dachev MCP Java Decompiler Server 1.2.0 through 1.2.4 allows remote attackers to execute commands. The decompileFromJar path in index.js interpolates the untrusted jarFilePath value into execPromise shell strings for JAR listing and extraction. An unauthenticated caller able to invoke the decompile-from-jar MCP tool can run commands with the server process's privileges, enabling host data access, modification, and service interruption.

CVSS severity7.3
High
EPSS probability1.82%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in Ivan Dachev MCP Java Decompiler Server 1.2.0 through 1.2.4 allows remote attackers to execute commands. The decompileFromJar path in index.js interpolates the untrusted jarFilePath value into execPromise shell strings for JAR listing and extraction. An unauthenticated caller able to invoke the decompile-from-jar MCP tool can run commands with the server process's privileges, enabling host data access, modification, and service interruption.

The record

CVE
CVE-2026-5802
Published
Apr 8, 2026
Updated
Apr 8, 2026
Vendor
Ivan Dachev
Product
MCP Java Decompiler Server
Classifications
CWE-78, CWE-77, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.2.0
  2. Affected versionversion=1.2.1
  3. Affected versionversion=1.2.2
  4. Affected versionversion=1.2.3
  5. Affected versionversion=1.2.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Ivan Dachev · MCP Java Decompiler Serverversion=1.2.0; version=1.2.1; version=1.2.2; version=1.2.3; version=1.2.4

Published CVSS scores

7.5VulDBAV:N/AC:L/Au:N/C:P/I:P/A:P
7.3VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
5.5VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1059Command and Scripting Interpreter

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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