What is CVE-2023-38831?

CVE-2023-38831 is RARLAB WinRAR Code Execution Vulnerability. The supplied enrichment data classifies it as Remote Code Exec mapped to CWE-351 CWE-351; CWE-345 CWE-345.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Yes: CISA KEV signal present. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

Is there a public exploit?

1 public PoC repositories reported; 0 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with EDR process telemetry, host service logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2023-38831 using CVSS 7.8, EPSS 98%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

Publicly linked actor or ransomware signals in the supplied enrichment data: Ransomware use: Known. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Treat as emergency remediation because CISA KEV status is present. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

CISA KEVRansomwarehighRemote Code Execpublic exploit

CVE-2023-38831

CVE-2023-38831 — RARLAB WinRAR Code Execution Vulnerability

Q: Is it in CISA KEV?

Yes. The supplied enrichment data lists CVE-2023-38831 in CISA KEV with required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

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.

Published Aug 23, 2023Updated Jun 17, 2026Sources: NVD, CISA, FIRST EPSS

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Confirmed

CISA KEV, listed Aug 24, 2023

EPSS

98%

top of FIRST's scoreset

Affects

rarlab

winrar

CVSS base

7.8

high

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

Active

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade winrar to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

CISA required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Federal deadline Sep 14, 2023 — passed 1,096 days ago

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Treat as emergency remediation because CISA KEV status is present.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
rarlab	winrar	—	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

High

Confidentiality

High

Integrity

High

Scope

Unchanged

Attack Complexity

Low

Attack Vector

Local

Privileges Req

None

User Interaction

Required

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
7.8	CVSS 3.1	high	1.8	5.9	NVD, CNA

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Weakness & attack patterns

CWE-351
CWE-345

Inferred from the weakness class — not observed against this CVE.

CAPEC-242 · Code InjectionCAPEC-35 · Leverage Executable Code in Non-Executable Files

T1557.002Adversary-in-the-Middle: ARP Cache Poisoning
T1584.002Compromise Infrastructure: DNS Server
T1491Defacement

CISA KEV details

CISA lists a CVE here once it has evidence of exploitation against real targets.

CISAThat month →

Listed

Aug 24, 2023

Federal deadline

Sep 14, 2023

passed 1,096 days ago

Ransomware use

Known

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a date to argue against.

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Exploit entries

Exploit-DB and CTI exploit indexes

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Monitor for scanner or exploit-pattern traffic after 1 public PoC repositories were reported.

EDR process telemetryhost service logs

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 7.8 (AV:L)
Jun 17, 2026 · NVD
2023
Added to CISA KEV catalog
Aug 24, 2023 · CISA
Initial · CVE published
Aug 23, 2023 · NVD

References

8 on the record

packetstormsecurity.com/files/174573/WinRAR-Remote-Code-Execution.html
Exploit, Third Party Advisory, VDB Entry
blog.google/threat-analysis-group/government-backed-actors-exploiting-winrar-vulnerability/
Exploit, Third Party Advisory
news.ycombinator.com/item?id=37236100
Issue Tracking
www.bleepingcomputer.com/news/security/winrar-zero-day-exploited-since-april-to-hack-trading-accounts/
Exploit, Press/Media Coverage, Third Party Advisory
www.group-ib.com/blog/cve-2023-38831-winrar-zero-day/
Exploit, Press/Media Coverage, Third Party Advisory
www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-38831
US Government Resource
www.win-rar.com/singlenewsview.html?&L=0&tx_ttnews%5Btt_news%5D=232&cHash=c5bf79590657e32554c6683296a8e8aa
Vendor Advisory
nvd.nist.gov/vuln/detail/CVE-2023-38831
Vendor Advisory

Elsewhere on this site

rarlabevery CVE for this vendor
August 2023what else CISA listed
Remote Code Execsame class
CWE-351other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2023-38831 is RARLAB WinRAR Code Execution Vulnerability, a high vulnerability affecting winrar from rarlab. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 1 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 7.8 describes technical severity, while EPSS 98% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.