CVE-2026-88265
Crun: crun: /dev/null symlink follow during stdio reopen allows host bind-mount write and chown
What happened?
A flaw was found in crun. After pivot_root, reopening /dev/null for stdio can follow a symlink and attach a host file to container stdio, then change that file's ownership. Affected versions are crun 1.29.1 and earlier. Default configurations that mount a fresh /dev are not exposed. No fixed release is available yet.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| crun-mainRed Hat | unaffected: 1.30-1.hum1 to < * | See vendor advisory |
| crunRed Hat | Default status: affected | See vendor advisory |
| container-tools:rhel8/crunRed Hat | Default status: affected | See vendor advisory |
| crunRed Hat | Default status: affected | See vendor advisory |
| crunRed Hat | Default status: affected | See vendor advisory |
| openshift/ose-rhel-coreos-8Red Hat | Default status: affected | See vendor advisory |
| openshift/ose-rhel-coreos-9Red Hat | Default status: affected | See vendor advisory |
| openshift/ose-rhel-coreos-9Red Hat | Default status: affected | 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.