Bug 2457326 (CVE-2026-40226)

Summary: CVE-2026-40226 systemd: systemd nspawn: Escape-to-host action via crafted config file
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: crizzo, jmitchel, kshier, teagle
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in nspawn, a container runtime environment within systemd. A local attacker or a process within an nspawn container could exploit this vulnerability by using a specially crafted optional configuration file. This could allow the attacker to escape the container's isolation and execute arbitrary actions on the host system.
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Description OSIDB Bzimport 2026-04-10 16:02:31 UTC
In nspawn in systemd 233 through 259 before 260, an escape-to-host action can occur via a crafted optional config file.