CVE-2026-24061 — telnetd in GNU Inetutils through 2

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

01What is this vulnerability?

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

02Affected products

No structured affected-product list available — see references below for vendor advisories.

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2026-01-26. Ransomware use: Unknown.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

Open in Sigma generator →

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2026-01-21T07:16:01.597
• Last modified: 2026-09-30T11:47:02.427
• Added to CISA KEV: 2026-01-26

09References

• codeberg.org — https://codeberg.org/inetutils/inetutils/commit/ccba9f748aa8d50a38d7748e2e60362e…
• codeberg.org — https://codeberg.org/inetutils/inetutils/commit/fd702c02497b2f398e739e3119bed0b2…
• lists.gnu.org — https://lists.gnu.org/archive/html/bug-inetutils/2026-01/msg00004.html
• redteam.ae — https://redteam.ae/blog/cve-2026-24061-inetutils-telnetd-root-bypass
• www.gnu.org — https://www.gnu.org/software/inetutils/
• www.openwall.com — https://www.openwall.com/lists/oss-security/2026/01/20/2
• www.openwall.com — https://www.openwall.com/lists/oss-security/2026/01/20/8
• www.vicarius.io — https://www.vicarius.io/vsociety/posts/cve-2026-24061-detection-script-remote-au…
• www.vicarius.io — https://www.vicarius.io/vsociety/posts/cve-2026-24061-mitigation-script-remote-a…
• www.openwall.com — http://www.openwall.com/lists/oss-security/2026/01/22/1