CVE-2023-38831: RARLAB WinRAR · n/a
Affects RARLAB WinRARSource CVE Database V5
Exploited in the wild · used in ransomware campaigns · KEV due 14 Sep 2023 · public exploit available (Metasploit) · 99% EPSS : upgrade to 6.23 now.
Data as of 25 Oct 2026, 19:02 UTC
- KEV deadline
- US federal agencies must patch by this date; a sensible deadline for everyone else.
- Ransomware
- Used in ransomware campaigns
- EPSS
- 99.8% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.23
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 23 Aug 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 1 day after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by mitre
, 29 days before disclosure
CVE published
on cve.org
, t = 0
Added to CISA KEV (opens in a new tab)
exploitation confirmed · ransomware use known
, 1 day after disclosure
KEV remediation due
US federal deadline
, 22 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Upgrade RARLAB WinRAR to 6.23.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| RARLAB WinRAR | Affected
| Fixed in
|
Description
CVE-2023-38831 is a high-severity remote code execution vulnerability affecting WinRAR versions prior to 6.23. The flaw allows an attacker to execute malicious code when a user opens a specially crafted ZIP archive containing a benign file and a folder with the same name. Exploitation requires user interaction but no privileges or authentication. This vulnerability was actively exploited in the wild from April to October 2023. The CVSS score of 7.8 reflects significant impact on confidentiality, integrity, and availability. European organizations using vulnerable WinRAR versions, especially those processing ZIP files from untrusted sources, are at risk. Mitigation involves updating WinRAR to version 6.23 or later and implementing strict archive handling policies.
References
- group-ib.com/blog/cve-2023-38831-winrar-zero-day/ (opens in a new tab)
- bleepingcomputer.com/news/security/winrar-zero-day-exploited-since-april-to-hack-trading-accounts/ (opens in a new tab)
- news.ycombinator.com/item?id=37236100 (opens in a new tab)
- packetstormsecurity.com/files/174573/WinRAR-Remote-Code-Execution.html (opens in a new tab)
- blog.google/threat-analysis-group/government-backed-actors-exploiting-winrar-vulnerability/ (opens in a new tab)
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-38831 (opens in a new tab)