Bug 2503686 (CVE-2026-16487)

Summary: CVE-2026-16487 bootc: containers-common: bootc: automatic updates can apply unsigned mutable-tag content under default containers policy
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, security-response-team, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in bootc when operating with the default containers signature policy. Automatic or manual upgrades of a mutable image tag may apply unsigned content for registries that fall through to insecureAcceptAnything, allowing an attacker who can update that tag to execute arbitrary OS content as the host root filesystem on reboot.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2555373, 2555374    
Bug Blocks:    
Deadline: 2026-10-10   

Description OSIDB Bzimport 2026-07-21 15:46:38 UTC 
A flaw was found in RHEL image-mode (bootc) update handling when used with the default containers signature policy. Hosts enrolled to a mutable image tag can automatically fetch and apply updated content for that tag via bootc upgrade / bootc-fetch-apply-updates without signature verification for registries that fall through to insecureAcceptAnything. An attacker who can publish content to the enrolled mutable reference can cause the host to reboot into attacker-controlled OS content running as host root. bootc rollback does not revert persistent /var state written during the malicious deployment window, so naive rollback remediation may leave attacker persistence intact.