Infinite loop in junrar - #VU139362
Published: July 26, 2026
Vulnerability identifier: #VU139362
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-835
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper control flow management in the RarVM.ExecuteCode loop in src/main/java/com/github/junrar/unpack/vm/RarVM.java when extracting a crafted RAR4 archive containing jump instructions. A remote attacker can provide a specially crafted RAR archive to cause a denial of service.
The issue can cause an extraction thread to spin indefinitely, consuming CPU and blocking the process.
Affected software
junrar
Remediation
Install security update from vendor's website.
junrar - update to 7.6.1