{"id":"CVE-2026-56741","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-56741","generatedAt":"2026-10-28T04:32:37.428Z","title":"Prior to 3.30.14, 4.0.16, and 4.2.1, the JLine3 Telnet server remote-telnet module does not apply an upper bound to terminal dimensions received via the Telnet NAWS option, and TelnetIO.handleNAWS() in TelnetIO.java:856-879 reads client-supplied width…","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 apply an upper bound to terminal dimensions received via the Telnet NAWS option, and TelnetIO.handleNAWS() in TelnetIO.java:856-879 reads client-supplied width and height as 16-bit unsigned integers and passes values such as 65535x65535 to setTerminalGeometry(), allowing an unauthenticated remote attacker to repeatedly alternate values and trigger continuous expensive rendering work that causes CPU exhaustion and denial of service. This issue is fixed in versions 3.30.14, 4.0.16, and 4.2.1.","published":"2026-07-17T22:17:57.000Z","lastModified":"2026-10-24T20:10:00.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-400"],"affected":["jline/jline"],"epss":{"score":0.00595,"percentile":0.48247,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.60%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/jline/jline3/commit/3ea9cad8699714dc072fade29d36be0d1e23d708","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/commit/733eb353dca7b0ea0252e724445b6defa29c393e","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/commit/86b7ba7801988aadb1a67555629522a71d603bd3","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/pull/2000","tags":["Issue Tracking"],"source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/releases/tag/4.0.16","tags":["Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/releases/tag/4.2.1","tags":["Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/security/advisories/GHSA-2r2c-cx56-8933","tags":["Vendor Advisory","Exploit"],"source":"security-advisories@github.com"},{"url":"https://github.com/jline/jline3/security/advisories/GHSA-2r2c-cx56-8933","tags":["Vendor Advisory","Exploit"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-56741","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}