Local root escalation via unsanitized environment forwarding
Published Feb 27, 2026 · Updated Feb 27, 2026
Privilege escalation in GNU Inetutils telnetd through 2.7 allows local users to obtain a root shell through a crafted Telnet session. The start_login function in telnetd/pty.c forwards a client-set CREDENTIALS_DIRECTORY to util-linux login, which trusts login.noauth in that directory. Exploitation requires telnetd to invoke util-linux login 2.40 or later and an unprivileged local user to create a login.noauth file containing yes.
Summary
What happened
Privilege escalation in GNU Inetutils telnetd through 2.7 allows local users to obtain a root shell through a crafted Telnet session. The start_login function in telnetd/pty.c forwards a client-set CREDENTIALS_DIRECTORY to util-linux login, which trusts login.noauth in that directory. Exploitation requires telnetd to invoke util-linux login 2.40 or later and an unprivileged local user to create a login.noauth file containing yes.
The record
- CVE
- CVE-2026-28372
- Published
- Feb 27, 2026
- Updated
- Feb 27, 2026
- Vendor
- The GnuPG Project
- Product
- Inetutils
- Classifications
- CWE-829, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 27, 2026CVE publishedPublication date reported by the CVE source.
- Feb 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=2.7
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- telnet_lpe.py upstream disclosure attachmentfunctional · demonstrated
- GNU Inetutils telnetd privilege-escalation PoCproof of concept · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo