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

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-13 · updated 2026-10-14
Weakness: CWE-835

Description

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.

Affected products

Red Hat Cert Manager support for Red Hat OpenShift release 1.18: all versions — fixed in 1789029076, 1791459707, 1791459711, 1791459759, 1791966259
Red Hat OpenShift Container Platform 4.18: all versions — fixed in 418.94.202604140044-0
Red Hat AI Inference Server 3.2: all versions — fixed in 1775740563, 1780681984
Red Hat AI Inference Server 3.3: all versions — fixed in 1775680192, 1775680262, 1775749857, 1778244531, 1778244546, 1778244559
Red Hat Discovery 2: all versions — fixed in 1775668717, 1775675922
Red Hat Enterprise Linux 10: all versions — fixed in 0:3.7.7-5.el10_1
Red Hat Enterprise Linux 10.0 Extended Update Support: all versions — fixed in 0:3.7.7-5.el10_0
Red Hat Enterprise Linux 9: all versions — fixed in 0:3.5.3-7.el9_7
Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions: all versions — fixed in 0:3.5.3-2.el9_0.3
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions: all versions — fixed in 0:3.5.3-5.el9_2.1
Red Hat Enterprise Linux 9.4 Extended Update Support: all versions — fixed in 0:3.5.3-4.el9_4.2
Red Hat Enterprise Linux 9.6 Extended Update Support: all versions — fixed in 0:3.5.3-6.el9_6.1
Red Hat Hardened Images: all versions — fixed in 3.8.7-1.hum1
Red Hat Insights proxy 1.5: all versions — fixed in 1776868961
Red Hat OpenShift Container Platform 4.13: all versions — fixed in 413.92.202604080111-0
Red Hat OpenShift Container Platform 4.14: all versions — fixed in 414.92.202605060243-0
Red Hat OpenShift Container Platform 4.15: all versions — fixed in 415.92.202605060220-0
Red Hat OpenShift Container Platform 4.16: all versions — fixed in 416.94.202604211449-0
Red Hat OpenShift Container Platform 4.17: all versions — fixed in 417.94.202605112123-0
Red Hat OpenShift Container Platform 4.19: all versions — fixed in 4.19.9.6.202604211219-0
Red Hat Update Infrastructure 5: all versions — fixed in 1776868744, 1776868772, 1776868774, 1776868842

How to fix

Upgrade to a fixed version: Red Hat Cert Manager support for Red Hat OpenShift release 1.18 1789029076, 1791459707, 1791459711, 1791459759; Red Hat OpenShift Container Platform 4.18 418.94.202604140044-0; Red Hat AI Inference Server 3.2 1775740563, 1780681984; Red Hat AI Inference Server 3.3 1775680192, 1775680262, 1775749857, 1778244531; Red Hat Discovery 2 1775668717, 1775675922; Red Hat Enterprise Linux 10 0:3.7.7-5.el10_1; Red Hat Enterprise Linux 10.0 Extended Update Support 0:3.7.7-5.el10_0; Red Hat Enterprise Linux 9 0:3.5.3-7.el9_7; Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions 0:3.5.3-2.el9_0.3; Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:3.5.3-5.el9_2.1; Red Hat Enterprise Linux 9.4 Extended Update Support 0:3.5.3-4.el9_4.2; Red Hat Enterprise Linux 9.6 Extended Update Support 0:3.5.3-6.el9_6.1. Check the vendor advisory for mitigations.

References

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