Privilege escalation in Red Hat Enterprise Linux 10
CVE-2026-84042
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
Vulnerability class: Privilege Escalation
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.001 (0.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 1st percentile — 0.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: -0.000
Affected products
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-84042 (vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking)
- github.com/containers/crun/
Frequently asked questions
- What is CVE-2026-84042?
- CVE-2026-84042 is a high-severity vulnerability in Red Hat Enterprise Linux 10, classified under Improper Privilege Management. CVSS score: 7.8/10. Published 2026-09-10.
- How severe is CVE-2026-84042?
- High severity. CVSS v3 base score is 7.8 out of 10.