CVE-2026-84042: crun Ubuntu Improper Privilege Management
CVSS: 7.8v3.1HighAwaiting analysis
AliasesUBUNTU-CVE-2026-84042
Published 10-09-2026Last modified 15-09-2026
Vulnerability summary
CVE-2026-84042 is a high (CVSS 7.8) Improper Privilege Management vulnerability in crun Ubuntu. EPSS estimates a 0.10% chance of exploitation in the next 30 days, higher than 0.8% of scored vulnerabilities.
CVSS score
7.8/10
010
High · v3.1 (CVE.org)EPSS score
0.10%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 10-09-2026PublishedVulnerability first disclosed.
- 15-09-2026Last modifiedVulnerability information updated.
Description
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
CVSS metrics
3 scores · 3 sources · 1 versionHigh 7.8Preferred score · CVE.org (CNA)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:HSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS trend
Probability
0.10%
Chance of exploitation in the next 30 days
Percentile
1%
Versus all other CVEs
30-day change
0.00 pp
From 0.10% on 21-09-2026
21-09-202621-10-2026
EPSS score0.10%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu1 product
- crunAll versions (No fix recorded)
1 vendor · 1 product