CVE-2026-70637: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-6269-2q48-xxqm
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CVSS 5.9
CWE-820
Published
Advisory Summary

CVE-2026-70637 is a HIGH (CVSS 5.9) security vulnerability vulnerability (CWE-820: Missing Synchronization) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product utilizes a shared resource in a concurrent manner but does not attempt to synchronize access to the resource.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-70637 at a Glance

CVE Identifier CVE-2026-70637
GHSA Identifier GHSA-6269-2q48-xxqm
Severity HIGH
CVSS v3.1 Base Score 5.9
CWE Classification CWE-820: Missing Synchronization
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.9

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

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

How to Fix CVE-2026-70637

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-2026-70637, 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-820: Missing Synchronization, where the product utilizes a shared resource in a concurrent manner but does not attempt to synchronize access to the resource. 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

LightFTP through 2.4 contains multiple data race vulnerabilities in ftpserv.c that allow anonymous attackers to cause undefined behavior by issuing LIST followed by ABOR commands without authentication. The control thread closes data_socket and file_fd descriptors while worker threads concurrently operate on the same fields in worker_thread_cleanup, allowing stale file descriptors to be reassigned by the OS and subsequently used by worker threads on unrelated resources, resulting in potential denial of service.

References

NVD — CVE-2026-70637 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-70637
Software Source Repository REPOSITORY
https://github.com/hfiref0x/LightFTP/issues/75
www.vulncheck.com/advisories/lightftp... WEB
https://www.vulncheck.com/advisories/lightftp-data-race-condition-via-abor-command-in-ftpserv-c

Frequently Asked Questions

What is CVE-2026-70637?
CVE-2026-70637 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-820: Missing Synchronization.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-70637?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-70637?
CVE-2026-70637 has a CVSS v3.1 base score of 5.9 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-70637?
CVE-2026-70637 is classified under CWE-820: Missing Synchronization (The product utilizes a shared resource in a concurrent manner but does not attempt to synchronize access to the resource.).
How can I check Maven dependencies for CVE-2026-70637?
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-6269-2q48-xxqm",
  "modified" : "2026-08-06T15:32:49Z",
  "published" : "2026-08-06T15:32:49Z",
  "aliases" : [ "CVE-2026-70637" ],
  "details" : "LightFTP through 2.4 contains multiple data race vulnerabilities in ftpserv.c that allow anonymous attackers to cause undefined behavior by issuing LIST followed by ABOR commands without authentication. The control thread closes data_socket and file_fd descriptors while worker threads concurrently operate on the same fields in worker_thread_cleanup, allowing stale file descriptors to be reassigned by the OS and subsequently used by worker threads on unrelated resources, resulting in potential denial of service.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/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-2026-70637"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/hfiref0x/LightFTP/issues/75"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/lightftp-data-race-condition-via-abor-command-in-ftpserv-c"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-820" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-06T15:17:27Z"
  }
}