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CVE-2026-3184 Red Hat CVE debrief

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 vulnerability has a CVSS score of 3.7, indicating a Low severity. System administrators should be aware of this vulnerability and take necessary actions to mitigate it.

Vendor
Red Hat
Product
Red Hat Hardened Images
CVSS
LOW 3.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-03
Original CVE updated
2026-08-31
Advisory published
2026-04-03
Advisory updated
2026-08-31

Who should care

Users of the util-linux package, particularly those using the login utility with the `-h` option, should be aware of this vulnerability. System administrators who rely on host-based PAM access control rules may need to take action to mitigate this vulnerability. This includes reviewing and updating util-linux to the latest version, verifying and restricting access to the login utility, and monitoring system logs for suspicious activity.

Technical summary

The vulnerability is caused by improper hostname canonicalization in the `login(1)` utility. When invoked with the `-h` option, the utility can modify the supplied remote hostname before setting `PAM_RHOST`. This could allow a remote attacker to bypass host-based PAM access control rules that rely on fully qualified domain names. The affected product is util-linux, and the vulnerability has a CVSS score of 3.7, indicating a Low severity.

Defensive priority

Low

Recommended defensive actions

  • Review and update util-linux to the latest version
  • Verify and restrict access to the login utility
  • Monitor system logs for suspicious activity
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
  • Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
  • Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE record was published on 2026-04-03T19:17:23.377Z and was last modified on 2026-07-21T19:10:00.107Z. The NVD entry is currently Analyzed. This information is based on the provided source corpus. Further verification is recommended to ensure accuracy.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-3184 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-3184

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-3184 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-3184

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.