telnetd in GNU inetutils through 2.7 allows an out-of-bounds write in the LINEMODE SLC (Set Local Characters) suboption handler because add_slc does not check whether the buffer is full.

This Telnet flaw could be exploited by an unauthenticated attacker to achieve code execution. Immediate patching is strongly recommended.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - telnetd in GNU Inetutils through 2.7 allows remote authentication bypass via a "-f root" value for the
    USER environment variable. (CVE-2026-24061)

  - telnetd in GNU inetutils through 2.7 allows privilege escalation that can be exploited by abusing systemd
    service credentials support added to the login(1) implementation of util-linux in release 2.40. This is
    related to client control over the CREDENTIALS_DIRECTORY environment variable, and requires an
    unprivileged local user to create a login.noauth file. (CVE-2026-28372)

  - telnetd in GNU inetutils through 2.7 allows an out-of-bounds write in the LINEMODE SLC (Set Local
    Characters) suboption handler because add_slc does not check whether the buffer is full. (CVE-2026-32746)

  - telnet in GNU inetutils through 2.7 allows servers to read arbitrary environment variables from clients
    via NEW_ENVIRON SEND USERVAR. (CVE-2026-32772)

The remote Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8387-1 advisory.

    It was discovered that the Inetutils telnet daemon incorrectly handled the CREDENTIALS_DIRECTORY     environment variable. An attacker could possibly use this issue to escalate privileges. (CVE-2026-28372)

    It was discovered that the Inetutils telnet daemon did not properly validate buffer bounds when processing     LINEMODE SLC suboptions. An attacker could possibly use this issue to cause a denial of service or execute     arbitrary code. (CVE-2026-32746)

    It was discovered that the Inetutils telnet client incorrectly handled the NEW_ENVIRON SEND USERVAR     option. An attacker could possibly use this issue to read arbitrary environment variables.
    (CVE-2026-32772)

Tenable has extracted the preceding description block directly from the Ubuntu 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 Debian 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4527 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-4527-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                   Andreas Henriksson     April 11, 2026                                https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : inetutils     Version        : 2:2.0-1+deb11u4     CVE ID         : CVE-2026-28372 CVE-2026-32746 CVE-2026-32772     Debian Bug     : 1130741 1130742

    Several vulnerabilities were discovered in the inetutils implementation     of telnetd and telnet, which may result in privilege escalation or     information disclosure.

    CVE-2026-28372

        Ron Ben Yizhak from SafeBreach found that the fix for CVE-2026-24061 was         not complete and can be exploited by abusing systemd service credentials         support added to the login(1) implementation of util-linux in release 2.40.

        While Debian bullseye does not include util-linux 2.40 this problem does         thus not affect it, but was still addressed in case someone manually         updates util-linux and thus exposes this vulnerability.

    CVE-2026-32746

         Adiel Sol, Arad Inbar, Erez Cohen, Nir Somech, Ben Grinberg, Daniel Lubel          of DREAM Security Research Team found that the telnetd server has a buffer          overflow in the LINEMODE SLC (Set Local Characters) suboption handler.
         This can lead to potential pre-login remote code execution.

    CVE-2026-32772

        Justin Swartz discovered that telnet allows servers to read arbitrary         environment variables from clients via NEW_ENVIRON SEND USERVAR.
        This can lead to information disclosure.

    For Debian 11 bullseye, these problems have been fixed in version     2:2.0-1+deb11u4.

    We recommend that you upgrade your inetutils packages.

    For the detailed security status of inetutils please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/inetutils

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS     Attachment:
    signature.asc     Description: PGP signature

Tenable has extracted the preceding description block directly from the Debian 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 Debian 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6193 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6193-1                   security@debian.org     https://www.debian.org/security/                     Salvatore Bonaccorso     April 03, 2026                        https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : inetutils     CVE ID         : CVE-2026-32746 CVE-2026-32772     Debian Bug     : 1130741 1130742

    Several vulnerabilities were discovered in the inetutils implementation     of telnetd and telnet, which may result in privilege escalation or     information disclosure.

    For the oldstable distribution (bookworm), these problems have been fixed     in version 2:2.4-2+deb12u3.

    For the stable distribution (trixie), these problems have been fixed in     version 2:2.6-3+deb13u3.

    We recommend that you upgrade your inetutils packages.

    For the detailed security status of inetutils please refer to its     security tracker page at:
    https://security-tracker.debian.org/tracker/inetutils

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian 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 SUSE Linux SLES12 host has packages installed that are affected by a vulnerability as referenced in the SUSE- SU-2026:0930-1 advisory.

    This update for krb5-appl fixes the following issue:

    - CVE-2026-32746: Remote Pre-Auth Buffer Overflow in GNU Inetutils telnetd LINEMODE (bsc#1259691).

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

Note that Nessus has not tested for this issue 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 a vulnerability as referenced in the openSUSE- SU-2026:20374-1 advisory.

    Changes in krb5-appl:

    - CVE-2026-32746: Remote Pre-Auth Buffer Overflow in GNU Inetutils telnetd LINEMODE (bsc#1259691)

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

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

ID	Name	Product	Family	Type	Severity
474887	Alpine: multiple inetutils-telnet packages: security update to 2.8-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	Local	high
474887	Alpine: multiple inetutils-telnet packages: security update to 2.8-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	Local	high
320402	Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : Inetutils vulnerabilities (USN-8387-1)	Nessus	Ubuntu Local Security Checks	Local	high
307667	Debian dla-4527 : inetutils-ftp - security update	Nessus	Debian Local Security Checks	Local	high
304942	Debian dsa-6193 : inetutils-ftp - security update	Nessus	Debian Local Security Checks	Local	medium
303143	SUSE SLES12 Security Update : krb5-appl (SUSE-SU-2026:0930-1)	Nessus	SuSE Local Security Checks	Local	critical
303005	openSUSE 16 Security Update : krb5-appl (openSUSE-SU-2026:20374-1)	Nessus	SuSE Local Security Checks	Local	critical

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CVE-2026-32746

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