VULNERABILITY INTELLIGENCE
CVE-2026-56740
CVSS score7.5 HIGH
EPSS probability0.59%
CISA KEVNot currently listed
Published2026-07-17
Last modified2026-10-24
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Description
JLine is a Java library for handling console input. Prior to 3.30.14, 4.0.16, and 4.2.1, the JLine3 Telnet server remote-telnet module does not limit the number of environment variables a client may inject via the Telnet NEW-ENVIRON option, and TelnetIO.readNEVariables() in TelnetIO.java:1127-1180 stores each variable pair in a HashMap held by ConnectionData, allowing an unauthenticated attacker to flood unique variable pairs before the terminating IAC SE byte and exhaust JVM heap memory with an OutOfMemoryError. This issue is fixed in versions 3.30.14, 4.0.16, and 4.2.1.
Weakness classification
- security-advisories@github.com: CWE-400
Primary references
- security-advisories@github.com — Patch
- security-advisories@github.com — Patch
- security-advisories@github.com — Patch
- security-advisories@github.com — Issue Tracking
- security-advisories@github.com — Issue Tracking
- security-advisories@github.com — Release Notes
- security-advisories@github.com — Release Notes
- security-advisories@github.com — Release Notes
- security-advisories@github.com — Exploit, Vendor Advisory
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 — Exploit, Vendor Advisory