CVE-2026-123177
Description
A flaw was found in dnf5daemon-server. Unauthenticated D-Bus methods pass caller-controlled URL or .rpm path patterns into a root-privileged cmdline package loader that may store fetched content in a world-readable cache without size limits, or open local paths as root, allowing a local attacker to disclose privileged content and to deny service via disk exhaustion.
Statement
Red Hat Enterprise Linux is not affected: supported RHEL content does not ship dnf5daemon-server.
Mitigation
Until a fixed package is available, remove or disable dnf5daemon-server if GNOME Software / dnf5daemon-client is not required, or restrict system D-Bus access to org.rpm.dnf.v0 to trusted users. If non-root access to instance metadata is already blocked on a cloud host, also ensure the daemon cannot be used as a bypass, or disable the daemon. If exploitation cannot be ruled out, rotate exposed secrets (SSH host keys, service credentials, cloud role credentials where applicable) in addition to clearing /var/cache/dnf5daemon-server.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.4 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Changed | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:H
Red Hat CVSS v3 Score Explanation
Unauthenticated local D-Bus callers can use the root daemon as a confused deputy to disclose privileged content via world-readable cmdline cache and exhaust disk via unbounded downloads. S:C consistent with CVE-2024-2746 on the same daemon; I:N after ruling out sequential cache-poison integrity path.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
An attacker could read sensitive data, either by reading the data directly from a data store that is not restricted, or by accessing insufficiently-protected, privileged functionality to read the data.
Integrity
Technical Impact: Modify Application Data; Modify Files or Directories
An attacker could modify sensitive data, either by writing the data directly to a data store that is not restricted, or by accessing insufficiently-protected, privileged functionality to write the data.
Access Control
Technical Impact: Gain Privileges or Assume Identity; Bypass Protection Mechanism
An attacker could gain privileges by modifying or reading critical data directly, or by accessing privileged functionality.
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
An attacker could gain unauthorized access to resources on the system and excessively consume those resources, leading to a denial of service.
Acknowledgements
Red Hat would like to thank Adam Simuntis / adamm <a.simuntis@gmail.com> for reporting this issue.
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