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CVE-2026-16730 Red Hat CVE debrief

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-24T12:16:47.717Z and has not been modified since then. The NVD entry is currently Awaiting Analysis. This vulnerability affects dbus-broker, causing it to exit when the process file-descriptor limit is reached, leading to potential service denial to the desktop session. Local attackers can exploit this by opening many connections to the user session bus. Flatpak applications can reach the host session bus through the dbus proxy, increasing the attack surface. The issue is related to how dbus-broker handles file descriptor limits and peer setup, and there is a need for careful assessment and mitigation.

Vendor
Red Hat
Product
Red Hat Enterprise Linux 10
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-24
Original CVE updated
2026-09-10
Advisory published
2026-07-24
Advisory updated
2026-09-10

Who should care

System administrators and security teams responsible for dbus-broker installations, especially in environments with multiple local users or Flatpak applications, should be aware of this vulnerability and prepare for potential service disruptions.

Technical summary

The dbus-broker service handles peer setup using file descriptors. When the process file-descriptor limit is reached, EMFILE/ENFILE errors occur. These errors are handled as fatal failures, causing the broker to exit. A local attacker can exploit this by opening many connections to the user session bus, potentially denying service to the desktop session. Flatpak applications can reach the host session bus through the dbus proxy, increasing the attack surface.

Defensive priority

Local attackers may exploit this vulnerability to deny service to the desktop session by opening many connections to the user session bus, impacting availability.

Recommended defensive actions

  • Inventory and assess systems for dbus-broker usage and exposure to local attackers.
  • Implement monitoring to detect high file descriptor usage and potential EMFILE/ENFILE errors.
  • Apply vendor remediation when available to address the dbus-broker vulnerability.
  • Consider compensating controls such as rate limiting or connection tracking.
  • Review and update incident response plans to address potential service denial.

Evidence notes

The CVE-2026-16730 record indicates a flaw in dbus-broker where EMFILE/ENFILE errors during peer setup cause the broker to exit when the process file-descriptor limit is reached. A local attacker can exploit this by opening many connections to the user session bus, potentially denying service to the desktop session. This issue affects how dbus-broker handles file descriptor limits and peer setup.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-16730 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-16730

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

  • CVE-2026-16730 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-16730

    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.