CVE-2026-16445
Description
A flaw was found in dracut. A remote attacker on the adjacent network can exploit this vulnerability by providing specially crafted DHCP options, such as a malicious root-path, next-server, or bootfile name, to a system using dracut's NetworkManager-based initrd network module. These options are improperly handled and written into a temporary shell script without proper escaping, leading to command injection. This allows the attacker to achieve root code execution within the initramfs during system boot.
Statement
This is an Important vulnerability in dracut's NetworkManager-based initrd network module (nm-run.sh) that allows command injection via crafted DHCP options. An attacker on the adjacent network can exploit this by acting as a DHCP server and providing specially crafted DHCP options, leading to root code execution within the initramfs. This affects systems configured to boot using dracut's network-manager module with a DHCP-derived netroot (for example, NFS-root configurations).
Mitigation
Escape DHCP-derived values (root-path, next-server, dhcp-bootfile) with shell-safe quoting (for example printf '%q') before writing them to the generated dhcpopts file in modules.d/35network-manager/nm-run.sh. This approach is already used in dracut-057 and later, and is already present in the RHEL 8.10.z dracut-049-244.git20260529.el8_10 build.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | 7.5 |
| Attack Vector | Adjacent Network | N/A | Adjacent Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability,Non-Repudiation
Technical Impact: Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart; Read Files or Directories; Modify Files or Directories; Read Application Data; Modify Application Data; Hide Activities
Attackers could execute unauthorized operating system commands, which could then be used to disable the product, or read and modify data for which the attacker does not have permissions to access directly. Since the targeted application is directly executing the commands instead of the attacker, any malicious activities may appear to come from the application or the application's owner.
Acknowledgements
This issue was discovered by Pavel Valena (Red Hat).
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