CVE-2026-84042
Crun: crun: rootful krun with passt executes container payload as host root
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What happened?
A flaw was found in crun. When crun is built with libkrun and a container is started rootful with passt networking (krun.use_passt), crun can execute attacker-controlled payload from the container image with host root privileges. The issue is a regression in crun 1.29. It affects crun >= 1.29
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| crunRed Hat | Default status: affected | See vendor advisory |
| container-tools:rhel8/crunRed Hat | Default status: unaffected | See vendor advisory |
| crunRed Hat | Default status: affected | See vendor advisory |
| crunRed Hat | Default status: unaffected | See vendor advisory |
| crunRed Hat | Default status: unaffected | See vendor advisory |
| openshift/ose-rhel-coreos-8Red Hat | Default status: unaffected | See vendor advisory |
| openshift/ose-rhel-coreos-9Red Hat | Default status: unaffected | See vendor advisory |
| openshift/ose-rhel-coreos-9Red Hat | Default status: unaffected | See vendor advisory |
Version information comes from the source record and can include unaffected products and exceptions. Distribution packages may contain backported fixes: an older upstream version alone does not prove a server is affected.
Is it being exploited?
This CVE was not listed in the CISA catalogue at our last retrieval. This does not establish that exploitation is absent.
How to respond
- Confirm the product, installed package version, and any configuration requirements in the vendor advisory.
- Follow the vendor’s remediation or workaround guidance in the references below. Structured fixed-version data is unavailable here; the publisher’s description may include a fix or workaround.
- Restart affected services if required, then verify the running version. Known exploitation may warrant investigation as well as patching.