Assessment
Why it matters
CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 97.9%; technical severity is CVSS 9.8.
telnetd in GNU Inetutils through 2.7 allows remote authentication bypass via a "-f root" value for the USER environment variable.
Who should care
- Teams operating Debian Linux, InetUtils
- Vulnerability and exposure management teams
- Security operations teams monitoring exploitation activity
Response plan
What I would do
- Confirm whether Debian Linux, InetUtils is present in the environment.
- Identify affected versions and establish whether vulnerable services are exposed or reachable.
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Review relevant security telemetry for evidence of attempted or successful exploitation.
- Document the remediation decision and track it to verified completion.
Vendor remediation
Patch and remediation links
Use the vendor source below to confirm the correct fixed version, package or mitigation for your affected product.
Technical details
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CWE
- CWE-88
- Affected versions
- Debian Debian Linux (Version: 11.0); GNU InetUtils (Start Including: 1.9.3, End Including: 2.7)
- Published
- 21 January 2026
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
Signal timeline
- CVE published
- Added to CISA KEV
- Latest EPSS score: 97.9%
- Signal calculated at 85
External references
- Government advisory from www.cisa.gov
- Exploit information from www.labs.greynoise.io
- Third-party advisory from www.openwall.com
- Technical reference from www.openwall.com
- Third-party advisory from lists.debian.org
- Vendor advisory from lists.gnu.org
- Technical reference from www.gnu.org
- Technical reference from www.openwall.com
- Technical reference from www.openwall.com
- Third-party advisory from www.vicarius.io
- Mitigation guidance from www.vicarius.io