PatchTheCVECVE-2026-70637: LightFTP through 2.4 contains multiple data race vulnerabilities in ftpserv.c that allow anonymous attackers t
CVE-2026-70637 is a medium-severity flaw (CVSS 5.9) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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
Why this priority
- CISA SSVC: public proof of concept
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.9 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.4% (top 71%) |
| CISA exploited list | No |
| Weakness | CWE-820 |
| Published | 2026-08-06 |
| Last modified | 2026-10-24 |
Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
- Write-up: github.com/hfiref0x/LightFTP/issues/75
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-70637?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-70637 being exploited?
CVE-2026-70637 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-70637 affect?
CVE-2026-70637 affects affected software. Severity is medium (CVSS 5.9). 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
How urgent is CVE-2026-70637?
Priority 36/100. CISA SSVC: public proof of concept; Remotely exploitable, no login, no user action