LiveActive security incident?Get immediate response
CVE Record

CVE-2026-4111: Libarchive: infinite loop denial of service in rar5 decompression via archive_read_data() in libarchive

A flaw was identified in the RAR5 archive decompression logic of the libarchive library, specifically within the archive_read_data() processing path. When a specially crafted RAR5 archive is processed, the decompression routine may enter a state where internal logic prevents forward progress. This condition results in an infinite loop that continuously consumes CPU resources. Because the archive passes checksum validation and appears structurally valid, affected applications cannot detect the issue before processing. This can allow attackers to cause persistent denial-of-service conditions in services that automatically process archives.

HighCVSS 7.5Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-4111 is a denial-of-service flaw in libarchive's RAR5 decompression. A specially crafted archive can make processing loop indefinitely and consume CPU. The business risk is service disruption where systems automatically inspect or unpack archives.

Executive priority

Prioritize remediation for internet-facing or automated file-processing systems. This is availability-focused, not data theft, but it can disrupt services without authentication if untrusted archives are processed.

Technical view

The flaw is in libarchive RAR5 handling through archive_read_data(). A crafted but checksum-valid RAR5 archive can prevent forward progress, causing CWE-835 infinite loop behavior. Red Hat lists affected libarchive, RHCOS, and RH AI Inference Server package streams.

Likely exposure

Exposure is most likely on listed Red Hat RHEL, OpenShift RHCOS, and Red Hat AI Inference Server environments that process untrusted archives automatically, especially RAR5 files.

Exploitation context

The source bundle states KEV is false and provides no active exploitation evidence. Exploitation requires getting a crafted RAR5 archive processed by an affected service or workflow.

Researcher notes

Checksum validation does not reliably screen malicious samples because the archive can appear structurally valid. The key exposure question is whether affected libarchive code is reachable from automated RAR5 processing paths.

Mitigation direction

  • Apply relevant Red Hat RHSA updates for affected product streams.
  • Check Red Hat guidance for exact fixed builds and upgrade paths.
  • Temporarily restrict automated processing of untrusted RAR5 archives where feasible.
  • Run archive processing in resource-limited, isolated workers.
  • Add CPU timeouts and monitoring around archive ingestion jobs.

Validation and detection

  • Inventory Red Hat assets for affected libarchive, RHCOS, and RH AI package versions.
  • Identify services that call libarchive on user-supplied archives.
  • Confirm whether archive_read_data() paths can receive RAR5 content.
  • Verify applicable RHSA updates are installed or scheduled.
  • Monitor archive-processing workers for sustained CPU loops.
Prepared
Confidence
high
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-835: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
description · low confidence lookup

Container behavior lookup

The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-4111 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
7Timeline events
2ADP providers
31Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2026-4111Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. ADP timelineredhat-SADP

    Made public.

  2. Source timelineredhat

    Made public.

  3. ADP timelineredhat-SADP

    Reported to Red Hat.

  4. Source timelineredhat

    Reported to Red Hat.

  5. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  6. CVE publishedCVE Program

    The CVE record was published.

  7. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPlibarchive: Infinite Loop Denial of Service in RAR5 Decompression via archive_read_data() in libarchive
other:Red Hat severity ratingcvssV3_1
  • 2026-03-11T11:18:51.609Z: Reported to Red Hat.
  • 2026-03-11T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Red HatRed Hat Enterprise Linux 10libarchive, 0:3.7.7-5.el10_1affected
Red HatRed Hat Enterprise Linux 10.0 Extended Update Supportlibarchive, 0:3.7.7-5.el10_0affected
Red HatRed Hat Enterprise Linux 9libarchive, 0:3.5.3-7.el9_7affected
Red HatRed Hat Enterprise Linux 9libarchive, 0:3.5.3-7.el9_7affected
Red HatRed Hat Enterprise Linux 9.0 Update Services for SAP Solutionslibarchive, 0:3.5.3-2.el9_0.3affected
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP Solutionslibarchive, 0:3.5.3-5.el9_2.1affected
Red HatRed Hat Enterprise Linux 9.4 Extended Update Supportlibarchive, 0:3.5.3-4.el9_4.2affected
Red HatRed Hat Enterprise Linux 9.6 Extended Update Supportlibarchive, 0:3.5.3-6.el9_6.1affected
Red HatRed Hat OpenShift Container Platform 4.13rhcos, 413.92.202604080111-0affected
Red HatRed Hat OpenShift Container Platform 4.14rhcos, 414.92.202605060243-0affected
Red HatRed Hat OpenShift Container Platform 4.15rhcos, 415.92.202605060220-0affected
Red HatRed Hat OpenShift Container Platform 4.16rhcos, 416.94.202604211449-0affected
Red HatRed Hat OpenShift Container Platform 4.17rhcos, 417.94.202605112123-0affected
Red HatRed Hat OpenShift Container Platform 4.18rhcos, 418.94.202604140044-0affected
Red HatRed Hat OpenShift Container Platform 4.19rhcos, 4.19.9.6.202604211219-0affected
Red HatRed Hat AI Inference Server 3.2rhaiis/model-opt-cuda-rhel9, 1780681984affected
Red HatRed Hat AI Inference Server 3.2rhaiis/vllm-cuda-rhel9, 1775740563affected
Red HatRed Hat AI Inference Server 3.3rhaiis/model-opt-cuda-rhel9, 1778244559affected
Red HatRed Hat AI Inference Server 3.3rhaiis/vllm-rocm-rhel9, 1778244531affected
Red HatRed Hat AI Inference Server 3.3rhaiis/vllm-spyre-rhel9, 1778244546affected
Red HatRed Hat AI Inference Server 3.3rhaiis/vllm-cuda-rhel9, 1775680192affected
Red HatRed Hat AI Inference Server 3.3rhaiis/vllm-rocm-rhel9, 1775680262affected
Red HatRed Hat AI Inference Server 3.3rhaiis/model-opt-cuda-rhel9, 1775749857affected
Red HatRed Hat Discovery 2discovery/discovery-server-rhel9, 1775668717affected
Red HatRed Hat Discovery 2discovery/discovery-ui-rhel9, 1775675922affected
Red HatRed Hat Hardened Imageslibarchive-main, 3.8.7-1.hum1affected
Red HatRed Hat Insights proxy 1.5insights-proxy/insights-proxy-container-rhel9, 1776868961affected
Red HatRed Hat Update Infrastructure 5rhui5/cds-rhel9, 1776868774affected
Red HatRed Hat Update Infrastructure 5rhui5/haproxy-rhel9, 1776868744affected
Red HatRed Hat Update Infrastructure 5rhui5/installer-rhel9, 1776868772affected
Weakness

CWE details

CWE-835

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-835 · source CWE mapping

Loop with Unreachable Exit Condition ('Infinite Loop')

Loop with Unreachable Exit Condition ('Infinite Loop') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs