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.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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. (CVE-2026-56741)

The remote SUSE Linux SLES16 / SLES_SAP16 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:22856-1 advisory.

    - CVE-2026-56740: unauthenticated remote memory exhaustion via unbounded Telnet `NEW-ENVIRON` variables     (bsc#1269021).
    - CVE-2026-56741: unauthenticated remote DoS via Unbounded Telnet NAWS Terminal Geometry (bsc#1270083).

    Changes for jline3:

    - Update to upstream version 3.30.15

     - fix: guard regex matching against catastrophic backtracking        (ReDoS) (#2018, backport of #2012):
       * Adds SafeRegex utility with TimeoutCharSequence to enforce          wall-clock deadlines during regex matching
       * Fixes 8 locations across terminal, reader, and builtins          where user-controlled input could trigger catastrophic          backtracking
       * Addresses GHSA-r2xf-8xr9-62gw, GHSA-2v9w-34q6-wpqx,          GHSA-ph9c-7hw9-vhhw, GHSA-5q95-hrpc-m3w3      + fix: backport security hardening (#1986, #1995):
       * Create persisted history file with owner-only permissions
       * Use exclusive create for extracted native library temp files      + fix: warn on insecure permissions when history file created        concurrently

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote openSUSE 16 host has packages installed that are affected by multiple vulnerabilities as referenced in the openSUSE-SU-2026:21423-1 advisory.

    - CVE-2026-56740: unauthenticated remote memory exhaustion via unbounded Telnet `NEW-ENVIRON` variables     (bsc#1269021).
    - CVE-2026-56741: unauthenticated remote DoS via Unbounded Telnet NAWS Terminal Geometry (bsc#1270083).

    Changes for jline3:

    - Update to upstream version 3.30.15

     - fix: guard regex matching against catastrophic backtracking        (ReDoS) (#2018, backport of #2012):
       * Adds SafeRegex utility with TimeoutCharSequence to enforce          wall-clock deadlines during regex matching
       * Fixes 8 locations across terminal, reader, and builtins          where user-controlled input could trigger catastrophic          backtracking
       * Addresses GHSA-r2xf-8xr9-62gw, GHSA-2v9w-34q6-wpqx,          GHSA-ph9c-7hw9-vhhw, GHSA-5q95-hrpc-m3w3      + fix: backport security hardening (#1986, #1995):
       * Create persisted history file with owner-only permissions
       * Use exclusive create for extracted native library temp files      + fix: warn on insecure permissions when history file created        concurrently

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2026-56741)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
463785	Echo: org.jline:jline-remote-telnet: security update to 3.30.14	Tenable Cloud Security	Echo Local Security Checks	Local	high
463785	Echo: org.jline:jline-remote-telnet: security update to 3.30.14	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	high
330325	SUSE SLES16: jline3 / jline3-builtins / jline3-console / jline3-console-ui / etc (SUSE-SU-2026:22856-1)	Nessus	SuSE Local Security Checks	Local	high
329519	openSUSE 16: jline3 / jline3-builtins / jline3-console / jline3-console-ui / etc (openSUSE-SU-2026:21423-1)	Nessus	SuSE Local Security Checks	Local	high
327766	Linux Distros Unpatched Vulnerability : CVE-2026-56741	Nessus	Misc.	Local	high

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