CVE-2026-70637Public exploitNetwork attack vector

Service interruption via unsynchronized descriptor cleanup

Published Aug 6, 2026 · Updated Aug 6, 2026

Missing synchronization in LightFTP 2.4 and earlier allows remote attackers to interrupt service via unauthenticated LIST and ABOR commands. worker_thread_cleanup closes shared data_socket and file_fd descriptors before canceling the active transfer worker, which can continue using reassigned descriptors. An anonymous FTP session must race an active LIST worker; descriptor reuse can produce undefined behavior and service interruption.

CVSS severity8.2
High
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing synchronization in LightFTP 2.4 and earlier allows remote attackers to interrupt service via unauthenticated LIST and ABOR commands. worker_thread_cleanup closes shared data_socket and file_fd descriptors before canceling the active transfer worker, which can continue using reassigned descriptors. An anonymous FTP session must race an active LIST worker; descriptor reuse can produce undefined behavior and service interruption.

The record

CVE
CVE-2026-70637
Published
Aug 6, 2026
Updated
Aug 6, 2026
Vendor
LightFTP
Product
LightFTP
Classifications
CWE-820, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 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?

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

  1. Affected versionversion=0 <=2.4
  2. Affected versionversion=0 <=d28c5e08aa4bd128737d35cc6ee0f9630a910ed5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

LightFTP · LightFTPversion=0 <=2.4; version=0 <=d28c5e08aa4bd128737d35cc6ee0f9630a910ed5

Published CVSS scores

8.2VulnCheckCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
5.9VulnCheckCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

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-820Missing Synchronization
T1499.004Application or System Exploitation

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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