CVE-2026-32746
Published: 13 March 2026
Description
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.
Mitigating Controls (NIST 800-53 r5)AI
Requires timely remediation of the out-of-bounds write flaw in telnetd, directly eliminating the vulnerability through patching.
Implements memory protections like stack canaries, ASLR, and DEP to prevent exploitation of the buffer overflow for code execution.
Enforces least functionality by disabling unnecessary telnetd service, preventing remote attackers from reaching the vulnerable component.
Security SummaryAI
CVE-2026-32746 affects the telnetd daemon in GNU inetutils through version 2.7. The vulnerability is an out-of-bounds write in the LINEMODE SLC (Set Local Characters) suboption handler, caused by the add_slc function not checking whether the buffer is full. Classified as CWE-120, it has a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating critical severity due to its potential for severe memory corruption.
Any unauthenticated remote attacker with network access to the telnetd service can exploit this flaw with low complexity and no user interaction required. By sending a crafted LINEMODE SLC suboption during a telnet connection, the attacker triggers the out-of-bounds write, enabling high-impact effects such as arbitrary code execution, data tampering, or service crashes affecting confidentiality, integrity, and availability.
Advisories and discussions appear in the GNU inetutils bug mailing list (https://lists.gnu.org/archive/html/bug-inetutils/2026-03/msg00031.html), OSS-Security announcements (https://www.openwall.com/lists/oss-security/2026/03/12/4 and http://www.openwall.com/lists/oss-security/2026/03/14/1), and a GitHub repository with related analysis (https://github.com/watchtowrlabs/watchtowr-vs-telnetd-CVE-2026-32746). Security practitioners should review these for patch availability and mitigation guidance.
Details
- CWE(s)
Affected Products
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Out-of-bounds write in publicly reachable telnetd daemon enables unauthenticated remote code execution, directly matching initial access via exploitation of a public-facing network service.