CVE-2025-4437
MediumCVSS 5.7Exploitation Probability (EPSS)
Low risk15th percentile - higher than 15% of all known CVEs
Summary
There's a vulnerability in the CRI-O application where when a container is launched with securityContext.runAsUser specifying a non-existent user, CRI-O attempts to create the user, reading the container's entire /etc/passwd file into memory. If this file is excessively large, it can cause high memory consumption leading applications to be killed due to out-of-memory. As a result a denial-of-service can be achieved, possibly disrupting other pods and services running on the same host.
Risk Assessment
An attacker can cause memory exhaustion on the host, potentially leading to crashes of other containers and services, causing downtime.
Recommendation
Update CRI-O to a patched version and avoid running containers with non-existent user IDs.
Other vulnerabilities in CRI-O
See all- CVE-2026-17113Medium
CRI-O has a vulnerability in environment-variable handling during container creation. When a CreateContainer request has a nil Envs field, CRI-O uses unfiltered config.Env entries from the OCI image, which can cause a Go panic and crash the crio daemon. This occurs when an entry lacks '='.
- CVE-2026-15809High
A flaw was found in CRI-O where the fix for a previous vulnerability (CVE-2022-4318) was incorrect, allowing it to be bypassed. An attacker capable of setting environment variables on a container can inject a newline character into the HOME variable, enabling arbitrary lines to be added to /etc/passwd.
- CVE-2024-5154High
A flaw was found in cri-o. A malicious container can create a symbolic link to arbitrary files on the host via directory traversal (“../“). This flaw allows the container to read and write to arbitrary files on the host system.
Original NVD description (English source)
There's a vulnerability in the CRI-O application where when container is launched with securityContext.runAsUser specifying a non-existent user, CRI-O attempts to create the user, reading the container's entire /etc/passwd file into memory. If this file is excessively large, it can cause the a high memory consumption leading applications to be killed due to out-of-memory. As a result a denial-of-service can be achieved, possibly disrupting other pods and services running in the same host.