Description
Junrar is an open source Java RAR archive library. Prior to 7.6.1, RarVM.ExecuteCode in src/main/java/com/github/junrar/unpack/vm/RarVM.java can repeatedly execute a VM_JMP instruction whose target is greater than or equal to the prepared program's codeSize. The setIP() function returns success without changing the instruction pointer or decrementing maxOpCount, and the jump handler continues before loop-end accounting, leaving both values unchanged. A crafted RAR4 archive can therefore keep an extraction thread in an infinite CPU loop and exhaust archive-processing worker capacity. The RAR virtual machine does not expose native process execution, so the supported impact is availability loss rather than code execution. This issue is fixed in version 7.6.1.
Published: 2026-10-15
Score: 7.5 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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Remediation

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-h9h9-2rmf-rvhp Junrar: RarVM VM_JMP maxOpCount bypass causes infinite CPU loop during RAR4 extraction
History

Thu, 15 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Description Junrar is an open source Java RAR archive library. Prior to 7.6.1, RarVM.ExecuteCode in src/main/java/com/github/junrar/unpack/vm/RarVM.java can repeatedly execute a VM_JMP instruction whose target is greater than or equal to the prepared program's codeSize. The setIP() function returns success without changing the instruction pointer or decrementing maxOpCount, and the jump handler continues before loop-end accounting, leaving both values unchanged. A crafted RAR4 archive can therefore keep an extraction thread in an infinite CPU loop and exhaust archive-processing worker capacity. The RAR virtual machine does not expose native process execution, so the supported impact is availability loss rather than code execution. This issue is fixed in version 7.6.1.
Title Junrar: RarVM VM_JMP maxOpCount bypass causes infinite CPU loop during RAR4 extraction
Weaknesses CWE-835
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-15T18:17:26.167Z

Reserved: 2026-09-24T14:16:20.200Z

Link: CVE-2026-97370

cve-icon Vulnrichment

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cve-icon NVD

Status : Received

Published: 2026-10-15T19:17:49.983

Modified: 2026-10-15T19:17:49.983

Link: CVE-2026-97370

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses
  • CWE-835

    Loop with Unreachable Exit Condition ('Infinite Loop')