CRITICAL · CVSS 9.8 CISA Known Exploited Vulnerability Used in ransomware attacks

CVE-2026-24061

GNU InetUtils Argument Injection Vulnerability

GNU InetUtils

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

CVSS
9.8
CRITICAL
EPSS
97.9%
30-day exploitation
Ransomware groups
1
recorded exploiting
Published
21 Jan 2026
CWE-88

Ransomware groups exploiting CVE-2026-24061

Qilin 2,241 victims tracked

Qilin ransomware was first observed in July of 2022. Qilin Ransomware is written in Golang and supports multiple encryption modes; all of which are controlled by the operator. Qilin actors practice double extortion – demanding payment for a decryptor, as well

Exploitation is attributed to these groups across their recorded activity. It does not follow that every organisation they listed was reached through CVE-2026-24061 — the source data does not record an entry point per incident.

Exploitation status

CISA Known Exploited Vulnerabilities

Listed by CISA on 26 January 2026. US federal agencies were required to remediate it by 16 February 2026.

EPSS — exploitation probability

FIRST puts the probability of exploitation activity in the next 30 days at 97.9%, which is higher than 99.9% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Recent listings by these groups

Disclosures from the groups above, newest first.

Frequently asked questions

Is CVE-2026-24061 being exploited by ransomware groups?

Yes. CVE-2026-24061 is recorded as exploited by Qilin. Between them these groups account for 2,241 victim disclosures in this database.

What does CVE-2026-24061 affect?

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

How severe is CVE-2026-24061?

CVE-2026-24061 is rated CRITICAL with a CVSS base score of 9.8. EPSS puts the probability of exploitation in the next 30 days at 97.9%, higher than 99.9% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 16 February 2026.

How should organisations respond to CVE-2026-24061?

Apply the vendor patch for GNU InetUtils as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.