util-linux login(1) Hostname Canonicalization flaw bypassing PAM access
CVE-2026-3184 Published on April 3, 2026
Util-linux: util-linux: access control bypass due to improper hostname canonicalization
A flaw was found in util-linux. Improper hostname canonicalization in the `login(1)` utility, when invoked with the `-h` option, can modify the supplied remote hostname before setting `PAM_RHOST`. A remote attacker could exploit this by providing a specially crafted hostname, potentially bypassing host-based Pluggable Authentication Modules (PAM) access control rules that rely on fully qualified domain names. This could lead to unauthorized access.
Vulnerability Analysis
CVE-2026-3184 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, with no impact on integrity, and no impact on availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
Authentication Bypass by Alternate Name
The software performs authentication based on the name of a resource being accessed, or the name of the actor performing the access, but it does not properly check all possible names for that resource or actor.
Products Associated with CVE-2026-3184
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Affected Versions
Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 7: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat Hardened Images: Red Hat OpenShift Container Platform 4:Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.