CVE-2026-15816

Publication date 7 August 2026

Last updated 28 September 2026

Ubuntu priority

Cvss 3 Severity Score

Description

A flaw was found in dracut. The die() error-handling function writes its message into a shell script under the initramfs emergency-hook directory without properly shell-quoting it. When the message contains data derived from the DHCP ROOT_PATH option, an attacker on the adjacent network who controls a rogue DHCP server can inject a command-substitution sequence that executes as root the next time dracut sources its emergency hook scripts during standard boot-failure handling.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
dracut	26.04 LTS resolute	Fixed 110-11ubuntu0.1
	24.04 LTS noble	Fixed 060+5-1ubuntu3.4
	22.04 LTS jammy	Fixed 051-1ubuntu0.1~esm1
	20.04 LTS focal	Fixed 048+80-2ubuntu0.1~esm1
	18.04 LTS bionic	Fixed 047-2ubuntu0.1~esm1
	16.04 LTS xenial	Fixed 044+3-3ubuntu0.1~esm1

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Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
dracut	Upstream: 207c339 Upstream: c4d5557

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.5 · High

Base metrics

Parameter	Value
Attack vector	Adjacent
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	High
Integrity impact	High
Availability impact	High

Scores

Parameter	Value
Base score	7.5 · High
Exploitability score	-
Impact score	-

Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

USN-8758-1
dracut vulnerability
14 September 2026

USN-8828-1
dracut vulnerabilities
28 September 2026