How severe is CVE-2023-38831?

CVE-2023-38831 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which products are affected by CVE-2023-38831?

CVE-2023-38831 affects the following products: rarlab winrar.

How do I patch CVE-2023-38831?

No patch has shipped for CVE-2023-38831 yet — track the rarlab winrar advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-2023-38831 across my infrastructure?

Inventory every rarlab winrar deployment and check each version against the affected-products list above.

How do I mitigate CVE-2023-38831 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Is CVE-2023-38831 actively exploited in the wild?

Yes. There are 53 known exploit references for CVE-2023-38831, including 31 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2023-38831?

CVE-2023-38831 has an EPSS (Exploit Prediction Scoring System) score of 99.8%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2023-38831 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2023-38831 (RARLAB WinRAR Code Execution Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2023-08-24. CISA required all US federal civilian agencies to remediate this vulnerability by 2023-09-14. The required action was: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. This CVE has been used in known ransomware campaigns. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2023-38831?

CVE-2023-38831 is classified as CWE-345 (CWE-345), CWE-351 (CWE-351). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2023-38831?

CVE-2023-38831 affects rarlab winrar. Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2023-38831 published, and has it been updated?

CVE-2023-38831 was published on August 23, 2023 and was last updated on August 5, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🛡️

CISA KEV · ACTIVELY EXPLOITED

HIGH severity

CVE-2023-38831 — WINRAR

HIGH

CVE-2023-38831 is a high-severity (CVSS 7.8) CWE-345 vulnerability in rarlab winrar. It is in CISA's Known Exploited Vulnerabilities catalog (added 2023-08-24) and has been used in ransomware campaigns — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.

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…

Published

Aug 23, 2023

Updated

Aug 5, 2026

Affected

1 product

Patched

See advisory

Exploits

53 known

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2023-08-24 — including use in ransomware campaigns. Federal agencies were required to remediate by 2023-09-14.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2023-38831.

EPSS Exploitation Probability

via FIRST.org ↗

99.8%probability of exploitation in next 30 days

Very High Risk0.00%

Lower risk than most CVEs100th percentile — riskier than 100% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2023-38831 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).

Where this sits among everything scored

Of 395,249 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.

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.

Affected Products

1 product · 1 configurations

Application

winrarrarlab

all

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.