CVE-2026-70637

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.

CVSS v4.0

8.2 HIGHCVSS: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

CVSS v3.1

5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.23% chance of exploitation in the next 30 days, 13th percentile

Published

2026-08-06

Updated

2026-08-14

Proof-of-concept exploits (1)

• hfiref0x/LightFTP/issues/75

References

• CVE Record
• NVD entry

Related

• CVE-2015-1701
• CVE-2017-1000218
• CVE-2017-15303
• CVE-2026-70636
• CVE-2026-70638
• CVE-2026-7063