CVE-2018-20251: RARLAB WinRAR

Medium severity, CVSS 5.5. EPSS: 31.4% chance of exploitation in the next 30 days.

In WinRAR versions prior to and including 5.61, there is path traversal vulnerability when crafting the filename field of the ACE format. The UNACE module (UNACEV2.dll) creates files and folders as written in the filename field even when WinRAR validator noticed the traversal attempt and requestd to abort the extraction process. the operation is cancelled only after the folders and files were created but prior to them being written, therefore allowing the attacker to create empty files and folders everywhere in the file system.

Affected products

• RARLAB WinRAR: up to and including 5.61

Published 2019-02-05. Last modified 2026-06-17.