Missing Release of File Descriptor or Handle after Effective Lifetime in jline3 - #VU148448
Published: September 9, 2026
Vulnerability identifier: #VU148448
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-775
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 missing release of a file descriptor after its effective lifetime in the JLine3 Telnet server ConnectionManager.makeConnection() method when handling connections after the maximum connection limit is reached. A remote attacker can repeatedly open TCP connections while the server is at capacity to exhaust the per-process file descriptor limit.
Only applications that embed the remote-telnet module and expose its Telnet server are affected.
Affected software
jline3
Remediation
Install security update from vendor's website.
jline3 - update to 4.4.3