Public vulnerability disclosure

CVE-2026-16460

Bootc: ostree: bootc/ostree: staged deployments not revalidated against container signature policy before finalization

publishedCWE-345

A flaw was found in bootc and ostree. Already-staged deployments are finalized without revalidating the deployment's container image against the current containers signature policy. Unsigned OS content staged under a prior permissive policy can remain bootable after policy is hardened to reject unsigned images, leading to full host compromise on reboot.

Technical severity7.4 highCVSS 3.1 · CNA: redhat
Published2026-10-19Source updated 2026-11-04
Collected2026-11-042 attributed sources

Fixes and workarounds

Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. --- CME Mitigation Guidance (2026-10-20) --- Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure. The highest-value action is to revalidate container image signatures against active container signature policy before finalizing or booting staged ostree deployments in bootc and ostree: upgrade to the fixed Bootc/Ostree/Rpm Ostree/Rust Zincati builds, which revalidates container image signatures against the active container signature policy in /etc/containers/policy.json before finalizing or booting already-staged ostree deployments, closing all 2 injection vectors (host reboot into pending staged deployment, bootc upgrade --from-downloaded deployment application). Until patched, this is only a concern on Linux systems using bootc or ostree, including RHEL image-mode hosts — Non-Linux platforms are unaffected — so Clear all existing staged ostree deployments immediately after hardening /etc/containers/policy.json and ensure unsigned container images are never staged. As a compensating measure, Run SELinux in enforcing mode to confine processes running from finalized deployments to defined domains and Deploy IMA/EVM appraisal to verify executable file signatures at runtime and block untrusted binaries. These controls limit blast radius and contain exploitation, but they do not fix the underlying missing signature revalidation defect — apply the upstream patch to fully remediate. Highest-impact CME: CME-712 Container Image Signing and Provenance Verification (Cosign/Sigstore) (high)

Source: CNA: redhat

Affected products and versions

Affected products, source version ranges and reporting authorities
ProductVersionsAuthority
Red Hat Enterprise Linux 10
Red Hat
bootc
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat Enterprise Linux 10
Red Hat
ostree
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat Enterprise Linux 10
Red Hat
rpm-ostree
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat Enterprise Linux 8
Red Hat
ostree
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat Enterprise Linux 9
Red Hat
bootc
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat Enterprise Linux 9
Red Hat
ostree
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat Enterprise Linux 9
Red Hat
rpm-ostree
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat Hardened Images
Red Hat
bootc
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat Hardened Images
Red Hat
ostree
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat OpenShift Container Platform 4
Red Hat
openshift/ose-rhel-coreos-8
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat OpenShift Container Platform 4
Red Hat
openshift/ose-rhel-coreos-9
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat OpenShift Container Platform 4
Red Hat
ostree
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat OpenShift Container Platform 5
Red Hat
openshift/ose-rhel-coreos-9
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat OpenShift Container Platform 5
Red Hat
ostree
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / scoreVectorAuthority
3.1 / 7.4
high
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HCNA: redhat

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

For agents and automation

Read public disclosures for free as Markdown or JSON. Compatible browsers also expose native WebMCP tools to search disclosures, read this page, and discover API access.

Use the ontology-linked Cyber API with x402 pay per request, or a Y2 Pro or Elite API key with the intel:cyber scope.

Endpoints and access details

https://api.y2.dev/api/v2/cyber/cves
https://api.y2.dev/api/v2/cyber/cves/{cveId}

A workspace owner or admin can create a Pro or Elite API key. Send Authorization: Bearer <Y2_API_KEY> from your trusted agent runtime.

For x402, omit Authorization and read the HTTP 402 payment challenge before signing a retry. Public browser tools do not make payments.

Agent access JSON · OpenAPI · CVE API guide