CVE-2026-97370

Junrar: RarVM VM_JMP maxOpCount bypass causes infinite CPU loop during RAR4 extraction

HIGH
7.5
CVSS Score
Published: October 15, 2026 at 06:17 PM UTC
Updated: October 16, 2026 at 08:04 PM UTC
1 product affected across 1 vendorJunrar

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Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 7.6.1

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-835

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