Junrar up to 7.6.0 Virtual Machine RarVM.java RarVM.ExecuteCode infinite loop

Summaryinfo

A vulnerability was found in Junrar up to 7.6.0. It has been rated as problematic. This affects the function RarVM.ExecuteCode of the file src/main/java/com/github/junrar/unpack/vm/RarVM.java of the component Virtual Machine. The manipulation leads to infinite loop. This vulnerability is documented as CVE-2026-97370. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Junrar up to 7.6.0 and classified as problematic. This issue affects the function RarVM.ExecuteCode of the file src/main/java/com/github/junrar/unpack/vm/RarVM.java of the component Virtual Machine. The manipulation with an unknown input leads to a infinite loop vulnerability. Using CWE to declare the problem leads to CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. Impacted is availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-97370 since 09/24/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 7.6.1 eliminates this vulnerability.

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Productinfo

Name

• Junrar

Version

• 7.0
• 7.1
• 7.2
• 7.3
• 7.4
• 7.5
• 7.6.0

Website

• Product: https://github.com/junrar/junrar/

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