CVE-2026-23953: linuxcontainers incus CRLF Injection

Vulnerability summary

CVE-2026-23953 is a high (CVSS 8.7) CRLF Injection vulnerability in linuxcontainers incus. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 40.8% of scored vulnerabilities. 2 public exploits are recorded.

Timeline

1. 22-01-2026
   PublishedVulnerability first disclosed.
2. 26-01-2026
   Last modifiedVulnerability information updated.

Description

Incus is a system container and virtual machine manager. In versions 6.20.0 and below, a user with the ability to launch a container with a custom YAML configuration (e.g a member of the ‘incus’ group) can create an environment variable containing newlines, which can be used to add additional configuration items in the container’s lxc.conf due to newline injection. This can allow adding arbitrary lifecycle hooks, ultimately resulting in arbitrary command execution on the host. Exploiting this issue on IncusOS requires a slight modification of the payload to change to a different writable directory for the validation step (e.g /tmp). This can be confirmed with a second container with /tmp mounted from the host (A privileged action for validation only). A fix is planned for versions 6.0.6 and 6.21.0, but they have not been released at the time of publication.

• CWE-93Improper Neutralization of CRLF Sequences ('CRLF Injection')The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.