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.
Conclusion & alert: CVE-2018-20251 is rated High Exploit Risk (62/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.65%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-18 | 0.55% | 0.65% | +0.10% |
| 2 | 2026-01-06 | 0.57% | 0.55% | -0.02% |
| 3 | 2025-12-14 | — | 0.57% | — |
Full EPSS history (15 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.5 | 3.0 | MEDIUM |
|
1.8 | 3.6 | [email protected] |
| 4.3 | 2.0 | MEDIUM |
|
8.6 | 2.9 | [email protected] |
| URL | Tags |
|---|---|
| http://www.securityfocus.com/bid/106948 | Third Party Advisory VDB Entry |
| https://research.checkpoint.com/extracting-code-execution-from-winrar/ | Exploit Third Party Advisory |
| https://www.win-rar.com/whatsnew.html | Release Notes Vendor Advisory |