{"items":[{"id":"NVI-00014073","kind":"vulnerability","title":"JLine3 Telnet server: Unauthenticated Remote DoS via Unbounded Telnet NAWS Terminal Geometry","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected.","NVD lastModified does not establish freshness of every associated CPE record."],"lifecycle":"active","identifiers":["GHSA-2r2c-cx56-8933","CVE-2026-56741"],"plain_summary":"GitHub lists this reviewed advisory for org.jline:jline-remote-telnet, org.jline:jline-remote-telnet, org.jline:jline-remote-telnet. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-5df7ee700130dc196419fc7ac113fc45"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-09-01T21:02:04.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-3e5baa73f0cf2f48195470660df0c645"},{"kind":"CVSS","as_of":"2026-10-24T20:10:00.137Z","value":"7.5 HIGH (3.1)","meaning":"security-advisories@github.com severity; no combined Null risk score.","source_id":"sr-5df7ee700130dc196419fc7ac113fc45"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-3e5baa73f0cf2f48195470660df0c645","url":"https://github.com/advisories/GHSA-2r2c-cx56-8933","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-2r2c-cx56-8933","publisher":"GitHub Advisory Database","observed_at":"2026-11-02T02:21:50.763Z"},{"id":"sr-5df7ee700130dc196419fc7ac113fc45","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56741","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2026-56741","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-08T01:48:33.286Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-3e5baa73f0cf2f48195470660df0c645"],"technology":"org.jline:jline-remote-telnet","known_exclusions":[],"conditions_summary":"### Summary\n\nThe JLine3 Telnet server (`remote-telnet` module) does not apply an upper bound to\nterminal dimensions received via the Telnet NAWS (Negotiate About Window Size) option.\nAn unauthenticated remote attacker can send a NAWS subnegotiation advertising a\n65535×65535 terminal and repeatedly alternate values to trigger continuous, expensive\nrendering work on the server, causing CPU exhaustion and denial of service.\n\n### Details\n\n`TelnetIO.handleNAWS()` (TelnetIO.java:856-879) reads the client-supplied width and\nheight as 16-bit unsigned integers and passes them to `setTerminalGeometry()`:\n\n```java\n// TelnetIO.java:869-875\nprivate void setTerminalGeometry(int columns, int rows) {\n    if (columns < SMALLEST_BELIEVABLE_WIDTH) columns = DEFAULT_WIDTH;  // lower bound only\n    if (rows    < SMALLEST_BELIEVABLE_HEIGHT) rows    = DEFAULT_HEIGHT;\n    connectionData.setTerminalGeometry(columns, rows);\n    connection.processConnectionEvent(\n        new ConnectionEvent(connection, ConnectionEvent.Type.CONNECTION_TERMINAL_GEOMETRY_CHANGED));\n}\n```\n\nOnly a *lower* bound is enforced (minimum 20 columns / 6 rows). Values up to 65535 are\naccepted and stored. The geometry change event propaga","public_affected_ranges":[">= 4.1.0, < 4.2.1"]},{"certainty":"source_listed","source_ids":["sr-3e5baa73f0cf2f48195470660df0c645"],"technology":"org.jline:jline-remote-telnet","known_exclusions":[],"conditions_summary":"### Summary\n\nThe JLine3 Telnet server (`remote-telnet` module) does not apply an upper bound to\nterminal dimensions received via the Telnet NAWS (Negotiate About Window Size) option.\nAn unauthenticated remote attacker can send a NAWS subnegotiation advertising a\n65535×65535 terminal and repeatedly alternate values to trigger continuous, expensive\nrendering work on the server, causing CPU exhaustion and denial of service.\n\n### Details\n\n`TelnetIO.handleNAWS()` (TelnetIO.java:856-879) reads the client-supplied width and\nheight as 16-bit unsigned integers and passes them to `setTerminalGeometry()`:\n\n```java\n// TelnetIO.java:869-875\nprivate void setTerminalGeometry(int columns, int rows) {\n    if (columns < SMALLEST_BELIEVABLE_WIDTH) columns = DEFAULT_WIDTH;  // lower bound only\n    if (rows    < SMALLEST_BELIEVABLE_HEIGHT) rows    = DEFAULT_HEIGHT;\n    connectionData.setTerminalGeometry(columns, rows);\n    connection.processConnectionEvent(\n        new ConnectionEvent(connection, ConnectionEvent.Type.CONNECTION_TERMINAL_GEOMETRY_CHANGED));\n}\n```\n\nOnly a *lower* bound is enforced (minimum 20 columns / 6 rows). Values up to 65535 are\naccepted and stored. The geometry change event propaga","public_affected_ranges":[">= 4.0.0, < 4.0.16"]},{"certainty":"source_listed","source_ids":["sr-3e5baa73f0cf2f48195470660df0c645"],"technology":"org.jline:jline-remote-telnet","known_exclusions":[],"conditions_summary":"### Summary\n\nThe JLine3 Telnet server (`remote-telnet` module) does not apply an upper bound to\nterminal dimensions received via the Telnet NAWS (Negotiate About Window Size) option.\nAn unauthenticated remote attacker can send a NAWS subnegotiation advertising a\n65535×65535 terminal and repeatedly alternate values to trigger continuous, expensive\nrendering work on the server, causing CPU exhaustion and denial of service.\n\n### Details\n\n`TelnetIO.handleNAWS()` (TelnetIO.java:856-879) reads the client-supplied width and\nheight as 16-bit unsigned integers and passes them to `setTerminalGeometry()`:\n\n```java\n// TelnetIO.java:869-875\nprivate void setTerminalGeometry(int columns, int rows) {\n    if (columns < SMALLEST_BELIEVABLE_WIDTH) columns = DEFAULT_WIDTH;  // lower bound only\n    if (rows    < SMALLEST_BELIEVABLE_HEIGHT) rows    = DEFAULT_HEIGHT;\n    connectionData.setTerminalGeometry(columns, rows);\n    connection.processConnectionEvent(\n        new ConnectionEvent(connection, ConnectionEvent.Type.CONNECTION_TERMINAL_GEOMETRY_CHANGED));\n}\n```\n\nOnly a *lower* bound is enforced (minimum 20 columns / 6 rows). Values up to 65535 are\naccepted and stored. The geometry change event propaga","public_affected_ranges":["< 3.30.14"]}],"null_published_at":"2026-11-08T19:53:44.060Z","source_updated_at":"2026-09-01T21:02:04.000Z","source_disclosed_at":"2026-06-18T13:07:16.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-11-02T02:21:50.763Z"},{"id":"NVI-00014073","kind":"vulnerability","title":"JLine3 Telnet server: Unauthenticated Remote DoS via Unbounded Telnet NAWS Terminal Geometry","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-2r2c-cx56-8933","CVE-2026-56741"],"plain_summary":"GitHub lists this reviewed advisory for org.jline:jline-remote-telnet, org.jline:jline-remote-telnet, org.jline:jline-remote-telnet. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-3e5baa73f0cf2f48195470660df0c645"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-09-01T21:02:04.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-3e5baa73f0cf2f48195470660df0c645"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-3e5baa73f0cf2f48195470660df0c645","url":"https://github.com/advisories/GHSA-2r2c-cx56-8933","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-2r2c-cx56-8933","publisher":"GitHub Advisory Database","observed_at":"2026-11-02T02:21:50.763Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-3e5baa73f0cf2f48195470660df0c645"],"technology":"org.jline:jline-remote-telnet","known_exclusions":[],"conditions_summary":"### Summary\n\nThe JLine3 Telnet server (`remote-telnet` module) does not apply an upper bound to\nterminal dimensions received via the Telnet NAWS (Negotiate About Window Size) option.\nAn unauthenticated remote attacker can send a NAWS subnegotiation advertising a\n65535×65535 terminal and repeatedly alternate values to trigger continuous, expensive\nrendering work on the server, causing CPU exhaustion and denial of service.\n\n### Details\n\n`TelnetIO.handleNAWS()` (TelnetIO.java:856-879) reads the client-supplied width and\nheight as 16-bit unsigned integers and passes them to `setTerminalGeometry()`:\n\n```java\n// TelnetIO.java:869-875\nprivate void setTerminalGeometry(int columns, int rows) {\n    if (columns < SMALLEST_BELIEVABLE_WIDTH) columns = DEFAULT_WIDTH;  // lower bound only\n    if (rows    < SMALLEST_BELIEVABLE_HEIGHT) rows    = DEFAULT_HEIGHT;\n    connectionData.setTerminalGeometry(columns, rows);\n    connection.processConnectionEvent(\n        new ConnectionEvent(connection, ConnectionEvent.Type.CONNECTION_TERMINAL_GEOMETRY_CHANGED));\n}\n```\n\nOnly a *lower* bound is enforced (minimum 20 columns / 6 rows). Values up to 65535 are\naccepted and stored. The geometry change event propaga","public_affected_ranges":[">= 4.1.0, < 4.2.1"]},{"certainty":"source_listed","source_ids":["sr-3e5baa73f0cf2f48195470660df0c645"],"technology":"org.jline:jline-remote-telnet","known_exclusions":[],"conditions_summary":"### Summary\n\nThe JLine3 Telnet server (`remote-telnet` module) does not apply an upper bound to\nterminal dimensions received via the Telnet NAWS (Negotiate About Window Size) option.\nAn unauthenticated remote attacker can send a NAWS subnegotiation advertising a\n65535×65535 terminal and repeatedly alternate values to trigger continuous, expensive\nrendering work on the server, causing CPU exhaustion and denial of service.\n\n### Details\n\n`TelnetIO.handleNAWS()` (TelnetIO.java:856-879) reads the client-supplied width and\nheight as 16-bit unsigned integers and passes them to `setTerminalGeometry()`:\n\n```java\n// TelnetIO.java:869-875\nprivate void setTerminalGeometry(int columns, int rows) {\n    if (columns < SMALLEST_BELIEVABLE_WIDTH) columns = DEFAULT_WIDTH;  // lower bound only\n    if (rows    < SMALLEST_BELIEVABLE_HEIGHT) rows    = DEFAULT_HEIGHT;\n    connectionData.setTerminalGeometry(columns, rows);\n    connection.processConnectionEvent(\n        new ConnectionEvent(connection, ConnectionEvent.Type.CONNECTION_TERMINAL_GEOMETRY_CHANGED));\n}\n```\n\nOnly a *lower* bound is enforced (minimum 20 columns / 6 rows). Values up to 65535 are\naccepted and stored. The geometry change event propaga","public_affected_ranges":[">= 4.0.0, < 4.0.16"]},{"certainty":"source_listed","source_ids":["sr-3e5baa73f0cf2f48195470660df0c645"],"technology":"org.jline:jline-remote-telnet","known_exclusions":[],"conditions_summary":"### Summary\n\nThe JLine3 Telnet server (`remote-telnet` module) does not apply an upper bound to\nterminal dimensions received via the Telnet NAWS (Negotiate About Window Size) option.\nAn unauthenticated remote attacker can send a NAWS subnegotiation advertising a\n65535×65535 terminal and repeatedly alternate values to trigger continuous, expensive\nrendering work on the server, causing CPU exhaustion and denial of service.\n\n### Details\n\n`TelnetIO.handleNAWS()` (TelnetIO.java:856-879) reads the client-supplied width and\nheight as 16-bit unsigned integers and passes them to `setTerminalGeometry()`:\n\n```java\n// TelnetIO.java:869-875\nprivate void setTerminalGeometry(int columns, int rows) {\n    if (columns < SMALLEST_BELIEVABLE_WIDTH) columns = DEFAULT_WIDTH;  // lower bound only\n    if (rows    < SMALLEST_BELIEVABLE_HEIGHT) rows    = DEFAULT_HEIGHT;\n    connectionData.setTerminalGeometry(columns, rows);\n    connection.processConnectionEvent(\n        new ConnectionEvent(connection, ConnectionEvent.Type.CONNECTION_TERMINAL_GEOMETRY_CHANGED));\n}\n```\n\nOnly a *lower* bound is enforced (minimum 20 columns / 6 rows). Values up to 65535 are\naccepted and stored. The geometry change event propaga","public_affected_ranges":["< 3.30.14"]}],"null_published_at":"2026-11-02T10:00:37.203Z","source_updated_at":"2026-09-01T21:02:04.000Z","source_disclosed_at":"2026-06-18T13:07:16.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-02T02:21:50.763Z"}],"next_cursor":null,"snapshot_revision":"42594"}