8.2
HIGH CVSS 4.0
CVE-2026-67607
LightFTP 2.3.1 Race Condition DoS via worker_thread_cleanup
Description

LightFTP 2.3.1 contains a race condition vulnerability that allows remote attackers to crash the server by racing a fresh connection that reuses the FTP context against an in-progress ABRT cleanup. Attackers can exploit the unprotected re-check of WorkerThreadId between worker_thread_cleanup() and pthread_join() outside of MTLock to cause pthread_join() to operate on an invalid thread ID, resulting in a server crash. CVE-2024-11144 identifies an incomplete fix of this vulnerability.

INFO

Published Date :

July 31, 2026, 4:17 p.m.

Last Modified :

July 31, 2026, 5:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-67607 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Hfiref0x lightftp
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 HIGH [email protected]
Solution
Address the race condition by properly synchronizing access to the FTP context during cleanup.
  • Apply vendor patches to fix the race condition vulnerability.
  • Ensure proper locking around worker thread cleanup logic.
  • Validate thread IDs before joining in cleanup routines.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-67607 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-67607 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-67607 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-67607 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 31, 2026

    Action Type Old Value New Value
    Added Reference https://github.com/zeroscience/tuktam#real-world-case-study-lightftp-cve-2024-11144
    Added SSVC {'id': 'CVE-2026-67607', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-31T16:17:22.619673Z'}
  • New CVE Received by [email protected]

    Jul. 31, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://github.com/hfiref0x/LightFTP', 'vendor': 'hfiref0x', 'product': 'LightFTP', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '2.3.1'}], 'packageURL': 'pkg:github/hfiref0x/LightFTP', 'defaultStatus': 'affected'}]
    Added Description LightFTP 2.3.1 contains a race condition vulnerability that allows remote attackers to crash the server by racing a fresh connection that reuses the FTP context against an in-progress ABRT cleanup. Attackers can exploit the unprotected re-check of WorkerThreadId between worker_thread_cleanup() and pthread_join() outside of MTLock to cause pthread_join() to operate on an invalid thread ID, resulting in a server crash. CVE-2024-11144 identifies an incomplete fix of this vulnerability.
    Added CVSS V4.0 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
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-367
    Added Reference https://github.com/zeroscience/tuktam#real-world-case-study-lightftp-cve-2024-11144
    Added Reference https://www.vulncheck.com/advisories/lightftp-race-condition-dos-via-worker-thread-cleanup
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.