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

Description

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

Affected Products

References

• https://www.openwall.com/lists/oss-security/2026/01/20/2
• https://www.openwall.com/lists/oss-security/2026/01/20/8
• https://www.gnu.org/software/inetutils/
• https://lists.gnu.org/archive/html/bug-inetutils/2026-01/msg00004.html
• https://codeberg.org/inetutils/inetutils/commit/fd702c02497b2f398e739e3119bed0b23dd7aa7b
• https://codeberg.org/inetutils/inetutils/commit/ccba9f748aa8d50a38d7748e2e60362edd6a32cc
• https://www.vicarius.io/vsociety/posts/cve-2026-24061-detection-script-remote-authentication-bypass-in-gnu-inetutils-package
• https://www.vicarius.io/vsociety/posts/cve-2026-24061-mitigation-script-remote-authentication-bypass-in-gnu-inetutils-package