CVE-2026-4111Public exploitNetwork attack vector

Service hang via oversized RAR5 filter block

Published Mar 13, 2026 · Updated Mar 13, 2026

Denial of service in libarchive's RAR5 reader allows remote attackers to hang archive-processing services with a crafted archive. The parse_filter() check accepts a filter block longer than half the decompression window, leaving the retry loop unable to advance or activate the filter. No authentication or user interaction is required when a service automatically processes uploaded archives, and each stuck worker continuously consumes CPU.

CVSS severity7.5
High
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in libarchive's RAR5 reader allows remote attackers to hang archive-processing services with a crafted archive. The parse_filter() check accepts a filter block longer than half the decompression window, leaving the retry loop unable to advance or activate the filter. No authentication or user interaction is required when a service automatically processes uploaded archives, and each stuck worker continuously consumes CPU.

The record

CVE
CVE-2026-4111
Published
Mar 13, 2026
Updated
Mar 13, 2026
Vendor
389 Directory Server
Product
Red Hat Enterprise Linux 10
Classifications
CWE-835, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

389 Directory Server · Red Hat Enterprise Linux 10Affected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 7Affected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Container PlatformAffected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.

Published CVSS scores

7.5Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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